Updated

Greece's Parliament was debating Thursday whether to launch criminal investigations into two former prime ministers and finance ministers over how leaked data on Greeks who banked in Switzerland was handled.

All three parties in the governing coalition have said they will vote late Thursday in favor of investigating former finance minister George Papaconstantinou, the main architect of Greece's first austerity program, for allegedly deleting the names of three of his relatives from the list and for breach of duty — offenses that could mean he goes to prison.

The main opposition left-wing Syriza party also wants the probe to include former finance minister Evangelos Venizelos, who currently heads one of the governing coalition parties, while the right-wing Independent Greeks also want investigations into former prime ministers George Papandreou and Lucas Papademos.

All four deny wrongdoing.

In 2010, when Greece's finances imploded, French authorities gave Papaconstantinou a list stolen from HSBC bank of about 2,000 Greeks with Swiss accounts, for a potential tax probe. But no action was taken.

When Athens requested a copy of the list from France last month, it emerged that three relatives of Papaconstantinou had been removed from the original.

Authorities' lack of action over the list and the suspicion it was doctored has fueled a furor at a time of harsh spending cuts, spiraling unemployment and falling wages, with successive governments accused of failing to crack down on tax evasion.

Papaconstantinou, who served as finance minister in 2009-2011, rejected any allegations of wrongdoing, insisting he did not make any changes to the data and that he was the target of a vicious smear campaign.

"I did not tamper with the data. It is inconceivable that I would have acted in such a way that would so blatantly involve me," he said in Parliament. His relatives have since given evidence to authorities that the funds in the Swiss accounts were legal and taxed, he noted.

Papaconstantinou insisted he had handed over the entire list, copied to a memory stick, to the financial crimes squad, and that he had not looked at the individual names. He said he gave the original CD of the list to staff in his office for safekeeping, and was unaware of what had become of it.

"Clearly the political responsibility is fully my own and it is clear that the issue should have been handled better," he said. "But it is unfortunate that my mishandling of this issue can be used an excuse for this process."

Papaconstantinou was expelled from his Socialist party, which is led by Venizelos, as soon as the missing names came to light.

The case over the data, dubbed the 'Lagarde List' in Greece, has riveted Greeks for weeks. The issue has expanded to involve two former heads of the financial crimes squad, who have appeared before prosecutors as suspects to explain their handling of the data and whether copies were made from one memory stick to another.

Papaconstantinou said he was at the "center of a crude effort" to fabricate guilty parties.

"I don't wish for anyone, not even my worst enemy, to live through what my family and I have lived through in the last few days," he said. "It is clear that some people want to make me a scapegoat."