International ratings agency Standard & Poor's said Monday there was a one-in-three chance of Greece leaving the eurozone in the coming months after June 17 polls.
"We believe there is at least a one-in-three chance of Greece exiting the eurozone in the coming months," if, for example, it were to reject the austerity measures and reforms agreed to in exchange for a massive EU-IMF bailout, S&P said.
Turning its back on the deal could lead to "a consequent suspension of external financial support," it said.
"Such an outcome would, in our view, seriously damage Greece's economy and fiscal position in the medium term and most likely lead to another Greek sovereign default."
Greece goes to the polls for the second time in six weeks on June 17 after an inconclusive vote on May 6 saw parties supporting the EU-IMF debt accord take a drubbing from voters hostile to endless austerity and higher taxes.
The June 17 vote has turned into a straight vote on the pact and the associated austerity measures, with the latest opinion polls showing those pro and against in a tight race which could have untold consequences for the future of the eurozone.