The Greek recession this year could be much worse than expected, with the economy shrinking by "more than seven percent," Prime Minister Antonis Samaras said Tuesday.

The central bank has previously estimated that the economy, now in its fifth year of recession, would shrink by 4.5 percent in 2012.

Samaras told conservative lawmakers that "our first goal is to stop the recession and start with recovery" as unemployment nears 24 percent.

The premier said that within four years, unemployment "can be lowered to ten percent," stressing that Greece remained committed to the terms of two EU-IMF bailout packages despite delays.

"We need to make up for these delays fast," Samaras said.

He then sharply criticised foreign officials who have estimated that Greece will not be able to stay in the 17-nation eurozone as "irresponsible."

"They undermine Greek efforts. We do what we can to get the country back on its feet and they do what they can for us to fail," he claimed.

Auditors from the European Union, International Monetary Fund and the European Central Bank return to Athens Tuesday to review progress made on the economic targets and reforms laid down in the country's bailout programme.

Greece has slipped on the targets and has argued that it should get more time to meet them, driving speculation that it might not get its next aid disbursement and so face having to leave the eurozone.