Rule changes may see peers expelled

Ministers are considering the moves as part of efforts to restore public faith in parliament after a series of scandals.

Justice Secretary Jack Straw confirmed that tighter conduct regulations for the House of Lords would be included in the forthcoming Constitution Renewal Bill.

He told Sky News: "In the House of Commons if you break the criminal law, or for example it is found that although you have not broken the criminal law, you have been doing something completely improper, then the House of Commons can in extremis expel you. And that must apply to the House of Lords."

Mr Straw refused to rule out making the changes retrospective, raising the prospect that they would cover peers embroiled in the recent cash-for-influence row - if allegations against them are proved.

Other disgraced Lords with criminal convictions would also faced being ejected, including author Lord Archer of Weston-super-Mare and newspaper mogul Lord Black of Crossharbour.

Jeffrey Archer received a four-year prison sentence for perjury and perverting the course of justice, while Conrad Black has been jailed in the US for fraud.

But Mr Straw suggested that merely changing the rules to allow members of the Upper House to resign may be enough.

"If you had simply provision for peers to resign then I think quite a number of those who were previously convicted would have resigned and that those who face these allegations may, as often is the case in business, for example, have been placed in a position in due course where they had no alternative but honourably to resign," he said.

Mr Straw is also expected to table proposals that would prevent peers sitting in the Lords if they are not paying tax in the UK. The issue is often raised by Labour backbenchers, who believe senior Tories such as Lord Ashcroft of Belize are "non-doms".