ATHENS, Greece (AFP) – Anti-austerity protesters hurled petrol bombs at police guarding the Greek Parliament Wednesday as MPs debated deeply unpopular reforms they need to vote in to clear the way for a eurozone rescue of Greece’s failing economy.

Riot police used tear gas to push back dozens of hooded protesters and secure the area in front of the Parliament building after the demonstrators’ Molotov cocktails set ablaze parts of Syntagma square in central Athens.

The street violence reflected broad public anger at measures now backed by Prime Minister Alexis Tsipras despite a July 5 referendum rejecting near-identical terms from Greece’s creditors.

Tsipras is facing a revolt over the reforms from his radical left-ruling Syriza party, which came to power in January on anti-austerity promises.

But the bills nevertheless looked likely to pass though Parliament with the support of pro-European Opposition parties.

Syriza’s hardline leftists, led by Energy Minister Panagiotis Lafazanis, were reported by Greek media to be ready to vote against the measures while calling for a return to the drachma.

Lafazanis himself insisted “several MPs including myself” would not approve the measures, but nevertheless said the party and Government would not be jeopardised.

If the sweeping changes to Greece’s taxes, pensions and labour rules are adopted, it could unlock a rescue of up to 86 billion euros (US$94 billion) agreed by eurozone leaders on Monday – as long as some other European parliaments also give their okay.

But the viability of the bailout was in doubt after the International Monetary Fund issued a stark warning that Greece’s creditors will have to go “far beyond” existing estimates for debt relief – an issue eurozone hawks such as Germany have already rejected out of hand.

Tsipras has said he did “not believe in” the deal but agreed to sign it “to avoid disaster” as his country teetered on the brink of economic collapse.

His finance minister, Euclid Tsakalotos, said during Wednesday’s parliamentary debate that his decision to also back the bailout terms was something that “will burden me my whole life”.

He added: “I don’t know if we did the right thing. I do know we did something we felt we had no choice over.”