Tony Blair has “short-changed British citizens” by signing a “lopsided” extradition treaty with the US, Liberal Democrat Nick Clegg has told MPs.

Mr Clegg was granted a rare emergency Commons debate as three British bankers prepare to be sent to the US for trial over an alleged fraud.

He told MPs it was easier to extradite people from the UK than the US.

Mr Blair insists the three men would have been extradited under the old rules, and says they will get bail.

Pressed about the issue at prime minister’s questions, Mr Blair said: “In the attorney general’s view, the test that is applied by the United States, the one of probable cause, is roughly analogous to the one we apply in this country.”

He said the “case for extradition was originally mounted under the old law, not the new law”.

“I do not believe it would be right if we ended up applying a higher standard and burden of proof to America than we do to many other countries,” he told MPs.

‘Tip of the Iceberg’

He said he “totally understood the concerns” of the three men’s families, but said the US prosecutors had promised to grant them bail while they awaited trial, provided they met conditions.

But, speaking as he opened the emergency debate on the issue, Mr Clegg said Mr Blair’s claims were “simply and totally incorrect”.

The government had admitted that the treaty was not reciprocal but backpedalled on this position when the NatWest Three case hit the headlines, said the Lib Dem home affairs spokesman.

And he added: “They are just the tip of the iceberg, their case has highlighted a wider problem.

“Namely that the government signed a lopsided treaty which short changes the interests of British citizens and those under our judicial protection.”

He called on the government to revoke existing extradition agreements with the US and renegotiate them.

‘Similar’

On Tuesday the government was defeated in the Lords, when peers called for extraditions to the US to be suspended.

Critics say the extradition laws are unfair because British citizens can be sent to the US without proof of the case against them - but there is no reciprocal arrangement.

They add that Britain should not enforce a treaty which the Americans have failed to ratify.

But the government argues that the arrangement means both countries have to produce an equivalent level of legal evidence when seeking extradition from the other nation.

Solicitor General Mike O’Brien told MPs the two systems were “not identical but very similar” and there was “a broad level of fairness in the Extradition Act”.

‘Biggest fraud’

He also said it was a “myth” that the NatWest Three case was about allegations arising from the UK only, as claimed by the Conservatives.

“They are innocent until proven guilty, but remember that in the US, Enron was the biggest fraud in history,” said Mr O’Brien.

Shadow attorney general Dominic Grieve, for the Conservatives, said the government should suspend extradition to the US until Washington agreed to ratify the 2003 extradition treaty.

Home Office minister Baroness Scotland is flying to Washington on Wednesday to appeal to the Senate to ratify the 2003 treaty.

The three ex-NatWest bankers - David Bermingham, Gary Mulgrew and Giles Darby - are due to be extradited to the US on Thursday in relation to the collapse of the energy giant Enron.

They deny any wrongdoing but have lost their court battles to face trial in the UK.

Mr Bermingham said: “We have been trying for the last three years to get tried in the UK. These are serious allegations and I would welcome the opportunity to face them in court.

“The difficulty we have is that everything we need to defend this case is here in the UK. This is a UK matter and the US connection is tenuous at best.”

He said he saw himself as a victim to be sacrificed to the system before a change can be brought about.