So what is the point of Ken?

The meeting began with the usual courtesies and the Mayor greeted his guests with that affable, lopsided grin for which he is famous.

No one recalls now the exchange that detonated the explosion, but it came in a shockingly unexpected rush, an eruption of screaming, arm-waving and finger-pointing.

As his guests watched in frozen horror and his officials shifted nervously in their seats Ken Livingstone metamorphosed into a snapping, snarling brute. Across the table were some of the most distinguished elected representatives of London local government, there to argue against the Mayor's voracious demands for money.

They shrank back as he damned them for daring to defy the march of his ambitions, they avoided his wild eye as he accused them of being in league with his enemies. What those men, all local councillors, witnessed that day was a side of Ken (as we must always call him) that Londoners never see. It was frightening and it was ugly, but it was very real.

This was not the reassuring, cosy Ken of the advertising hoardings and TV soundbites, the man who by sheer weight of personality prevailed against the will of a powerful government. It was Ken at bay, raging against his own impotence, gripped by paranoia and, most importantly, facing the awful truth that what he promised he would do for London simply isn't happening.

One of his old friends caught sight of him leaving his office late at night recently. He said: "He looked completely, utterly drained. I was shocked."

This week marks the halfway point in Ken's historic first term. His honeymoon is over and the reckoning is due. For years Livingstone, obsessed by power, had angled to 'control something'. Becoming London's mayor was his last chance to prove himself.

The Mayor's office has become a labyrinth of task forces, initiatives, mayoral commissions, advisers: the list grows daily. Against this background council tax is up, Ken is surrounding himself with special advisers, the Tube is still in turmoil, the threat of the congestion charge experiment looms, and driving in London has never been worse with rigged traffic lights and "counter-productive traffic-calming" measures that have brought many of London's main thoroughfares to a grinding halt.

So what has been achieved? There have been successes. Ken has encouraged building schemes that include affordable housing; grants have helped boost a flagging tourist industry hit hard by the September terrorism attacks in the United States. The London Development Agency, charged with regenerating areas of deprivation, has made a good start. And Ken has also given us London's first St Patrick's Day festival. He loves a good party.

Ken says he has vastly improved bus services. Against the national trend, passenger figures show a six per cent increase. But at what cost? The Mayor's budget for bus services started at £89 million and is now running at more than £300 million. Most of the money comes from government grants. He has funded a police recruitment campaign that will strengthen the Metropolitan by 1,000 more officers a year, but again this is only possible with government money.

Significantly, however, no one can recall Livingstone making an impact on fighting crime in London, a vital issue for its inhabitants. Instead he proudly boasts about raising taxi fares far beyond the pockets of ordinary Londoners.

Aides of the Mayor point proudly to the changes in London's taxi service as evidence of his effectiveness. Ken's Transport for London took over the duties of the Public Carriage Office and in an attempt to coax more drivers on to the streets at night authorised a major hike in fares. An immediate result of this was the anger of passengers being told to pay, for example, £28.50 for a six-mile ride from Notting Hill to Highbury. And the increase may have contributed to Ken's own £2,000-a-year taxi bill.

He is still a champion of public transport, of course, but the life he leads now calls for the occasional cab ride. Friends like Helen Mirren, Eddie Izzard and Joan Collins cannot always be found on a handy bus route. A feature of Ken's first half-term has been his fondness for mixing with celebrities, and why not? As Mayor, he is a celebrity.

In his baggy jackets and scuffed shoes he brings his own peculiar dress code to some of the best parties in town. He took a three-week holiday in Australia last month with Emma Beal who once helped organise his dining-out column in ES, the Evening Standard's weekly magazine. The thirtysomething Ms Beal now runs Ken's personal office. They have been seeing each other since last November when he split from Kate Allen, his partner of 20 years. "He's in love," a well-placed source says.

Some believe Ms Beal exercises a soothing influence on the 56-year-old Mayor. If so, he will certainly appreciate her qualities, for the first two years have taken a toll.

Ken made transport his priority, but his first half-term has been dominated by the bruising fight against the Government's plan to part-privatise the Tube.

It was a struggle that began with Ken at his combative best. The people - and it must be said, this newspaper - were with him, but now there is an uneasy sense of something obsessive, a creepy feeling that judgment has been flawed by fixated thinking. The Government made its position clear from the beginning and there was only ever a slim hope of defeating the PPP policy. Yet Ken still doesn't have a fallback position. He has staked everything on his transport commissioner Bob Kiley, the wunderkind he hired from New York, a man who has said again and again that PPP will not and cannot succeed.

This leaves London facing the dreadful prospect of having its Tube run by a transport commissioner who thinks the policy forced upon him is unworkable.

"Ken should have allowed some room for manoeuvre," said a transport analyst who has watched the PPP drama unfold. "He is now completely boxed in and the reason is he put ideology above pragmatism."

The question of Ken and ideology inevitably inspires thoughts of the old GLC and his loony-Left period. Intriguingly, the photograph on his railpass is from that era. Is that the way Ken still likes to think of himself? This is a worry for some. They say the Mayor's office is beginning to resemble the Gothic construct of stratagems and intrigue, alliances and hostilities that was the old County Hall. Comrade Ken still lurks beneath that cuddly, voterfriendly image, it is said.

Certainly, he has lost none of his taste for photo-opportunities. He adores the glamour of showbusiness. When Fat Boy Slim hosted a benefit concert for Ken's campaign, the mayor-to-be leaped onto the stage and danced wildly.

It is hard to reconcile this image with the idea of Ken behind closed doors, raging against those he perceives to be his enemies. But there is a view that he needs conflict to survive.

Hostilities between the mayor's office and the Association of London Government, the umbrella group for London councils, reached crisis point last year when Ken accused the body of trying to undermine his efforts. He resigned from the ALG in a fit of pique and then tried to bypass it by dealing directly with individual boroughs. It was a grave miscalculation.

The London boroughs were in despair over his increasing demands for money and angry over attempts to dictate to them on matters such as asylum seekers and domestic violence. Some councillors accused him of trying to foist his passÈ Left-wing dogma on to them.

But the major concern was money. Ken, who has never created a single penny's wealth in his entire career, is brilliant at spending other people's hard-earned money. Ken's two budgets so far have appalled councils. He has powers to raise money from a council tax precept to help fund the police, the fire brigade, regeneration and the running of the Greater London Authority. For the average household this meant a council tax increase of £122 in his first year. Now, after further demands from Ken, the extra that Londoners pay stands at £173. It would have been as much as £200 if he had had his way but the boroughs resisted his demands.

The effect of this precept has taken the tax bill for even modest homes to more than £1,000 across London, infuriating boroughs which have been fighting to keep it below this psychological barrier. Barnet recently sent out leaflets bearing a picture of a smirking Ken above the words: "GLA precept increases agreed without consulting local people." Wandsworth calculates that on current evidence councils could face demands that will increase by 20 per cent year on year.

It might be imagined that members of the London Assembly are delighted with Ken's success in filling the coffers. In fact, he is at war with them, too. Many believe he is operating an autocracy, ignoring their views and following his own agenda. His decision to press ahead with his scheme for congestion charging in the face of opposition from the assembly tends to confirm this.

So, too, does the mayoral style that has evolved over the past two years. Ken cannot count on the assembly for political support. He has few friends in Westminster, and even fewer in the boroughs. This does not dismay him, indeed he thrives on it. He is often called " oppositionist", a word which describes a politician who is at his best in adversity and confrontation. This is all too true, to the extent that since he became Mayor, Ken has created a whole climate of conflict in which his distinct style can flourish.

But he cannot go to war alone and, in the absence of political allies which the assembly was designed to provide, he has simply hired the friends he needs. He is currently planning a new tier of five advisers - to be called "executive directors" - who will be answerable only to him. Some of them are already on his staff and the new Policy Integration and Service Delivery Unit is being seen as a way of boosting the salaries of these individuals to around £70,000 a year.

These are the people who put the Mayor's ideas into action, and they follow his political doctrine to the letter. This has created yet more conflict.

Staff at Romney House, the old government office building that currently houses the GLA, are aghast at the prospect of taking instructions from the Mayor's cronies, people who have not been elected but have a very definite political agenda.

Ken doesn't care. He gives the impression that if, like Caligula, he wanted to give a top job to his horse, he would do so. He has a deputy, the experienced Labour assembly member Nicky Gavron. But when he went to Australia on holiday last month he left his chief of staff Simon Fletcher in charge. Mr Fletcher enjoys Ken's confidence, perhaps because he has been his loyal and trusted aide through many a battle. In Ken's memorable statement on the matter, Ms Gavron learned she would only inherit his power if he were to drop dead.

He shrugs off criticism of his rule, but the assembly's Standards Committee is furious that he holds meetings with developers behind closed doors, and makes planning decisions without consulting assembly members whose constituencies are affected. There is a move to report him to the new Standards Board for England, recently set up to investigate misconduct by elected politicians.

Nowhere is Ken's grip stronger than at Transport for London. The board, which is not elected, is chaired by him and there are serious concerns elsewhere in London government over its accountability. There is currently outrage in the boroughs over TfL's efforts to recruit traffic and transport professionals. The body is poaching experts from local councils with offers of salaries up to £15,000 higher than the boroughs can afford. Newham alone has lost two key staff recently, one of these is working on enforcement for congestion charging. This policy is Ken's last opportunity to make a Big Idea work and he is putting everything into it. Two years ago TfL had 2,257 staff. Now it has 3,142. The street management teams have been told congestion charging must work. No question. It is due to be introduced just before Ken stands for reelection in 2004 and its success or otherwise may well decide his future.

He and his retinue will soon move into the fastness of City Hall by London Bridge. This proud new symbol of London's latest experiment in self-government stands on the Thames, fortress-like and unassailable. It may give Ken comfort for now, but in two years' time he faces the people of London at the polls. If his dismal record has not improved, nothing will shield him from their fury.