Greece's pro-bailout conservative party has a narrow lead over the anti-austerity radical leftists, an opinion poll said Wednesday ahead of an election crucial for the debt-hit country's future.

The GPO poll for private Mega television gave the conservative New Democracy party 23.4 percent of the vote, just ahead of the leftwing Syriza with 22.1 percent.

The outcome of the 17 June election, the second in six weeks, will determine whether Greece is willing to complete vital reforms tied to a multi-billion EU-IMF loan agreement that has so far shielded the country from bankruptcy.

Syriza wants to reject many of the austerity measures stemming from the loan agreement but European leaders have warned that Greece could be starved of bailout funds if this happens.

There is growing speculation that Athens could be forced to leave the 17-member eurozone if the reforms falter, raising fears for the future of the single currency.

Over 80 percent of respondents in the GPO poll said Greece must stay in the eurozone "at all costs."

Some 52 percent said Greece should implement the rescue deal if it means keeping its place in the euro, but 77.8 percent want to amend the terms of the bailout—which many Greeks say has plunge the economy into recession.

Before leaving office this month, former Prime Minister Lucas Papademos warned Greece may run out of money by the end of June if international bailout funds are cut off following the election, a newspaper reported Sunday.

Other opinion polls on Sunday predicted a New Democracy victory with between 23.3 percent and 25.8 percent, a result that would require the party to seek partners to form a viable government.