Stocks have been hammered in Greece and borrowing costs continued to rise, amid renewed political uncertainty over the future of the country's bailout program.

Shares on the Athens Stock Exchange closed 5.7 percent lower Monday, falling below the 1,000-point mark to 948.21, while yields on Greece's 10-year bonds hit 7 percent after a months-long decline has driven the rate below 6 percent in September.

The bad news for government plans to end its bailout program two years early, came amid reluctance by creditors to back the move and fears the ruling conservatives might have to call an early general election in February.

The government needs opposition votes in parliament to elect a new president, and was trailing the anti-bailout Syriza party by 6.5 points in a survey published late Monday.