French authorities have disputed the Coalition Government's claims they effectively blocked prosecutions linked to the HSBC tax avoidance allegations.

French finance minister Michel Sapin said that he "did not understand" UK ministers' claims.

Earlier this week Conservative Treasury Minister David Gauke told MPs that there had been just one prosecution since his government was given the leaked files in 2010.

He also suggested that the lack of court cases had down to the strict terms set by the French.

But Mr Sapin told the French newspaper Le Monde: "I have not understood the comments made by the British authorities.

"The data on HSBC was transmitted to them in 2010, in the framework of the bilateral conventions that bind us. "Nothing has been said to them since. These conventions do restrict the use of the information to tax purposes.

"But if the British tax office wants to bring court cases, it is entitled to do so. The rest is a matter of judicial co-operation."

On Monday Mr Gauke told the Commons that the data has been handed over "under very strict conditions that limited the department's use of it to pursuing offshore tax evasion and prevented HM Revenue and Customs (HMRC) from sharing the data with other law enforcement authorities.

"Under these restrictions, HMRC has not been able to seek prosecution for other potential offences such as money laundering."

His comments were echoed by HMRC bosses when they gave evidence to the Commons Public Accounts Committee.

Labour Treasury spokeswoman Shabana Mahmood said: "David Gauke needs to urgently explain his claims in the House of Commons which now seem to have been contradicted by the French finance minister.

"The unanswered questions for ministers are mounting by the day. Why has there only been one prosecution out of 1,100 names? Did David Cameron and George Osborne discuss tax evasion at HSBC with (former Tory minister and one-time HSBC executive) Lord Green? Why did they appoint Lord Green as a Tory minister months after the Government received these files? And why did George Osborne and the Treasury sign a deal with the Swiss in 2012 which prevents the UK from actively obtaining similar information in the future?

"It is time we finally had answers from David Cameron and George Osborne on these questions."

As the row over tax avoidance continued, a member of the powerful Commons Treasury Committee said it would discuss hauling Lord Green before it to give evidence.

The Bank of England also said it could look in to allegations of tax avoidance at HSBC's Swiss subsidiary.

It also emerged that ministers had previously warned that UK nationals with Swiss bank accounts were "highly unlikely" to face criminal investigation for past tax-related offences if they made a one-off payment or voluntary disclosed their assets.

Details were also uncovered of an email thought to have been sent by whistle-blower Herve Falciani to HM Revenue and Customs as early as 2008.

As the political war over tax heated up, the Conservatives also called on Labour leader Ed Miliband to publish the legal document involved in his ownership of the family home.

Labour denies that Mr Miliband avoided tax through the arrangement - known as a deed of variation.

The party points out that Mr Miliband paid capital gains tax on his share of the north London property when he later sold it to his brother David.

Tory MP Andrew Bridgen described that denial as "risible" and said that the arrangement had been set up to avoid possible future inheritance tax liabilities.

He said: "Ed Miliband should now publish this deed of variation ... the public can then judge for themselves."

A Labour spokesman said that Mr Miliband paid capital gains tax at 40% on the sale of his share of the house.

Any suggestion that the Labour leader used the arrangement to avoid tax would be a "straightforward lie", he added.

The spokesman said: "Ed paid 40 per cent capital gains tax when the house was sold in 2004/05. It can't be tax avoidance if no tax was avoided."

Mr Miliband accused the Tories of seeking to use the document to "smear mud", adding: "It's something that my mother did 20 years ago, that was a decision she made.

"Let me just say this: I paid tax as a result of that transaction, I've avoided no tax in that."

Meanwhile, Nigel Farage claimed that Mr Miliband would "come to regret" describing David Cameron and Conservative donors as "dodgy" in the House of Commons.

One of those donors, former Conservative Treasurer Lord Fink later suggested that "everyone" avoided tax.