"During a telephone conversation with the Greek Central Bank Governor George Provopoulos, he informed me that the banks' situation was very difficult . . . and that the banking system was currently very weak," the Greek President said in a press statement issued from his palace.

"Withdrawals reached €700 million euros at 4:00 p.m on Monday," he noted, warning that the situation "would worsen in the next two days."

"Provopoulos said there was nothing to panic about, but that there were a lot of fears that could turn into panic," said Papoulias.

Greece's failure to form a government after a splinter vote at May 6 elections has stoked fears about the country's future in the eurozone.

The country is expected to hold fresh elections in June.

In February, former finance minister Evangelos Venizelos said Greeks deposited €16 billion euros overseas, including "32% in British banks and 10 per cent in Swiss banks."