Blair's reforms of 2005 to protect UK are yet to take effect

A raft of legal and practical reforms were promised or called for in the wake of the 7/7 attacks - but their implementation has been mixed, with some idea abandoned and others yet to come fully into effect.

In the immediate aftermath of the terrorist bombings which hit London's transport system exactly three years ago, then prime minister Tony Blair pledged an extensive legal shakeup - claiming that the "rules of the game" had changed - to make it easier to combat the threat posed by militant extremists.

Some of these proposed changes - such as the creation of a new offence of glorifying terrorism, the introduction of biometric visas and an overhaul of citizenship rules - have since been carried out.

But many other key promises have either not been delivered or have been undermined by subsequent legal rulings.

The abandoned ideas include a pledge to create new powers to enable the closure of places of worship in Britain which are being used to foment extremism, and a promise to outlaw the radical Islamist group Hizb ut-Tahrir.

However, the plan to amend human rights laws to ensure that potentially dangerous extremists could be deported has not materialised. This failure has been highlighted by recent court cases, including the release on bail of radical cleric Abu Qatada.

The use of control orders against British terror suspects who cannot be deported has been further undermined by successful court challenges which have significantly weakened the powers at ministers' disposal.

The same applies to the Government's efforts to reach agreements with countries such as Algeria, Libya and Jordan to ensure that extremists can be returned without the risk of torture. Although some such agreements have been reached, judicial rulings have largely wrecked their effectiveness. The result is that a significant number of extremists whom the Government wants to deport are still in the country.

On practical measures intended to improve the handling of any future emergency, there has been greater progress although gaps still remain.

On the key issue of communication on the London Underground system - which was a serious problem on the 7 July 2005 - new systems which allow the emergency services to keep in touch with each other on the Tube are being introduced. These have only been partly implemented however.

Measures have been taken to improve the provision of emergency supplies in the event of another attack and to ensure meeting points for survivors are available. Steps have also been taken ensure information about casualties is passed on more quickly to relatives and friends in a major emergency.