The comments come on the eve of much-awaited recommendations by the European Commission on Greece´s austerity plan, which aims to cut its budget deficit to below 3 percent of gross domestic product in 2012, from 12.7 percent in 2009.
Greece has been pounded by the markets for weeks, and the euro premium investors demanded for holding Greek debt rather than German bunds hit a lifetime high last week.
Papandreou told an economic conference the large spread between Greek government bond and German bunds was "completely unjustified" and was caused by a speculative attack that was strangling the economy.
The spread between Greek and German 10-year bonds stood at 343 basis points in early trading Tuesday.
the prime minister said that the country could not remain at the mercy of lenders and the dark winds of the markets adding that It needs to be able to define its own fate and its own course
Greece has won some respite since EU Economic and Monetary Affairs Commissioner Joaquin Almunia said Greece´s fiscal cutback plans were ambitious but achievable.
Papandreou said that they are determined to implement the stability plan to the letter, with persistence and consistency