If the troika does not approve the plan and agree that Greece is making sufficient progress reforming its finances, it means no more eurozone bailout funds.
And without bailout funds the country faces likely bankruptcy, ejection from the euro and social chaos.
The IMF is reportedly worried about becoming stuck as a long-term funder of the country, when its primary remit is to provide short-term, emergency funding.
So in Washington on Monday, IMF head Christine Lagarde suggested that eurozone countries may have to take a haircut on loans they have made to Greece, agreeing to write off part of what they are owed.
In addition, the ECB might also have to take losses on the estimated 40bn-euro worth of Greek bonds it owns.
Dr Vassilis Monastiriotis, senior lecturer at the European Institute of the London School of Economics, told the BBC: "If Greece convinces the authorities it is on track with its debt reduction measures, the decision to allow the two-year extension is easy - and by implication - the 15bn-euro funding that goes with it."
An EU summit on 18-19 October is expected to make a decision on the Greek extension request.
BBC 26 September 2012