SHADOW SYSTEMS

The centre-right New Democracy party and the centrist To Potami and the Socialist Pasok parties, which all backed Tsipras in parliamentary votes on the bailout this month, demanded a response to the reports.

"The revelations that are coming out raise a major political, economic and moral issue for the government which needs in-depth examination," it said in a statement.

"Is it true that a designated team in the finance ministry had undertaken work on a backup plan? Is it true they had planned to raid the national Mint and that they prepared for a parallel currency by hacking the tax registration numbers of the taxpayers?"

To Potami said the reports of covert plans were worthy of a bad thriller.

The Kathimerini report said access to the Greek tax service's computer systems was under the control of inspectors from the "troika", the international creditors' group, and therefore inaccessible to the government.

As a result, Varoufakis and an official in charge of information systems planned to copy taxpayer codes from online accounts and set up a shadow system. However, according to the report, he said the plan had never been approved by Tsipras.

Deputy Finance Minister Dimitris Mardas denied the government had ever discussed plans to take Greece out of the euro. "I have repeatedly said that such discussions have never taken place at a government policy level," he told Skai television.