Parliamentary debate today could lead to full-scale inquiry

The Speaker, John Bercow, yesterday opened the way to a full-scale parliamentary inquiry into whether phone-hacking has interfered with the business of government.

Mr Bercow announced that there is to be an emergency debate today, led by the Labour MP Chris Bryant, whose phone was hacked.

Simon Hughes, deputy leader of the Liberal Democrats, has told friends that he will use the occasion to break his self-imposed silence on the hacking. It was revealed at the trial of the News of the World reporter Clive Goodman and the private detective Glenn Mulcaire that Mr Hughes's phone was hacked.

Other known or suspected targets included the Cabinet ministers Tessa Jowell, Peter Mandelson and John Prescott, and London's Mayor, Boris Johnson, who was a shadow Tory minister at the time.

Mr Bryant will call for the issue to be investigated by the Commons Standards and Privileges committee for any evidence that the hacking of minsters' and MPs' phones had interfered with their political work.

Yesterday, Labour MPs were confident that the motion will be passed by the Commons. If it is, the Standards committee, chaired by the Labour MP Kevin Barron, will formally begin its enquiries on Tuesday.

One Commons inquiry into phone-tapping has already started. The Commons Home Affairs committee announced on Tuesday that it is looking into the law on phone-tapping and how the police enforce it.

A finding by the Standards committee that parliamentary privilege had been breached would be much more serious for those involved, because the Commons would have the power to compel witnesses to give evidence.

Yesterday, the Deputy Prime Minister, Nick Clegg, appealed to MPs not to "second guess" police enquiries into whether there is enough evidence to justify a new criminal investigation by Scotland Yard.

The New York Times published allegations by three former News of the World journalists suggesting that phone-hacking was more widespread than the newspaper has admitted, and that Mr Coulson was implicated during his four-year editorship.

Mr Coulson has flatly denied any involvement in illegal hacking, and has agreed to talk to police.

Standing in for David Cameron at Prime Minister's Questions, Mr Clegg said: "Phone-hacking is a very serious offence indeed. It is an outrageous invasion of privacy and it is right that two individuals were convicted and imprisoned.

"As for Mr Coulson, he has made it very, very clear that he took responsibility for something of which he had no knowledge at the News of the World and he refutes all the allegations that have been made to the contrary. That statement speaks for itself."