Big money for some, but at what cost to readers?

Here's a hot financial tip, fresh from the City desk, that's guaranteed to double your money overnight. It's such a sure bet, in fact, that the business staff at The Sunday Times and The Sunday Telegraph are talking about little else. And all you need do is wait for the phone to ring, and choose between whichever £200,000 offers are on the table.

There is a catch, of course. You need to be an established financial journalist whose name carries clout in City boardrooms. You must also be prepared to swap the buzz of a newsroom for the sales-led pressures of corporate public relations. But for Neil Bennett and Kirstie Hamilton, two of Fleet Street's most powerful business journalists, the lure of financial PR has proved irresistible in recent days - and many envious colleagues are now wondering how they too can cash in.

Bennett is leaving his post as The Sunday Telegraph's City editor to join the financial PR firm Gavin Anderson as a director, while Hamilton, doing the same job at The Sunday Times, is joining Tulchan Communications as a partner. According to the rumour mill, they stand to earn around £200,000 - with plenty more if they bring in the business. "I expect Neil has an arrangement whereby if he brings in new clients he could ratchet up his pay to £500,000," says the boss of one major PR firm who knows the going rate. "They're at the top of their profession, so will probably get £200,000 at the very least," agrees another senior financial PR.

"I came back from spending Christmas in New Zealand and just wasn't as excited about the stories," says Hamilton. "I thought it was time to do something else." Her basic salary will be boosted by potentially large bonuses, she says, as well as equity in the company.

Traditionally, many journalists have held the PR industry in some contempt, but it is not unknown for the stars to defect rather profitably to the other side. Roland Rudd left the Financial Times in 1994 to found Finsbury, the City PR firm that he sold five years later to Martin Sorrell's company, WPP, for up to £50 million. Rudd is still running the London office, although he has learned, he says, that his clients don't like him to be quoted in newspaper articles such as this one.

Others are less shy. Andrew Lorenz was Sunday Times business editor before he joined Financial Dynamics, where he represents clients such as Tate and Lyle. "They don't pay you for nothing," he warns. "You've got to perform. It's a mistake for journalists to come into this business because they see pound signs."

What makes the journalists so valuable to corporate clients is their understanding of how the newsroom works, and their contacts - not merely among former colleagues. "You'll have talked to so many CEOs and financial directors over the years, and that will be used to set up appointments to win new business," says one former journalist. "They're buying credibility - the kudos of that big name who can be wheeled into the meeting with the CEO," says another. But new recruits will need to cultivate diplomacy, and that frequently eludes a successful newspaper hack. "You need to be very flexible, broadminded and able to juggle a difficult client's many demands," says a woman who knows both worlds.

But is there a downside to the PR world filling up with big-name journalists? Some observers reckon that newspaper City pages are not quite as fearless as they once were. Call it laziness, complacency - or a too-cosy relationship between PRs and hacks - but there doesn't seem to be as much investigative journalism as there once was. Certainly, any PR who used to be a reporter will know how precisely to spoonfeed a lazy journalist. Certainly no new thalidomide-type scandal is going to result from a call from a pharmaceutical company PR.

For these reasons or others, some have found that the big bucks of PR do not suit them. Jeff Randall, now the BBC's business editor and another former Sunday Times City editor, moved to Financial Dynamics on a reported salary of £250,000. He soon moved back to journalism.

So what tips can we offer those journalists who hope to double their salaries? Choose your specialism carefully and you could earn between £70,000 and £150,000 if you're good, says David Brain, who started as a trainee on the Newcastle Journal and rose to be joint CEO of Weber Shandwick. Financial journalists are in most demand, followed by political correspondents. Healthcare is also valuable.

But think hard first. "After four months out of writing I started to pine," Jeff Randall confesses. "I'm a journalist at heart."