Greece's parliament is expected to approve last-ditch government proposals to its eurozone creditors aimed at preventing a dreaded exit from the eurozone.
The reforms proposed by the government have sparked criticism from hardline members of the radical left ruling party Syriza, but most opposition parties have expressed willingness to back them.
A majority of lawmakers from Syriza and other parties earlier on Friday (local time) granted their approval in a committee vote. The full plenary session vote is expected to be held early on Saturday morning.
"If the current deal comes to pass, it will be a difficult deal," new Finance Minister Euclid Tsakalotos warned lawmakers.
But he added that the government wanted parliament's approval "to strengthen the country's bargaining position, to achieve better terms in the agreement."
The latest reform proposals put forward by Athens were cheered by France and Italy on Friday, raising hopes that a last-ditch compromise can be reached to prevent a "Grexit."
In them Greek Prime Minister Alexis Tsipras concedes ground on major sticking points, including creditors' demands to overhaul pensions, increase sales taxes, and commit to privatisations.
But the proposed measures limit changes on other thorny issues, including tax breaks for Greece's islands and cuts to military spending.
Tsipras hopes his new offer will open the door to creditors discussing another round of relief from Greece's suffocating 320 billion euro ($A474 billion) mountain of debt.
The proposal aims to procure financing "for three years, debt adjustment and a front-loaded investment package of 35 billion euros," a Greek government source said.
But the Greek leader also risks alienating large numbers of the ruling party's supporters, who rejected in a national referendum last Sunday a very similar set of proposals put forward by Greece's creditors.
In a bid to head off a possible challenge to the measures within his hard-left party Syriza, Tsipras urged his lawmakers "to stand united and firm in front of these important decisions."
French President Francois Hollande said "the Greeks have shown a determination to want to stay in the eurozone because the program they are presenting is serious and credible."
However he cautioned that "nothing is decided yet."
Italian Prime Minister Matteo Renzi declared himself "more optimistic" that a deal would be done.
But Germany, leading a bloc of sceptical eurozone nations, said the outcome of crisis talks this weekend was "completely open."
The possibility of a breakthrough sent stock markets soaring in Europe, Asia and the US on Friday.
Eurogroup chief Jeroen Dijsselbloem promised that Eurozone finance ministers will make a 'major' decision Saturday on whether to endorse the latest proposals from Athens.
Tsipras is taking a political gamble by making any concessions to creditors' demands.
Hardliners in Syriza and coalition partner the Independent Greeks have obstinately rejected further austerity.
Although Greek voters last Sunday roundly voted "No" to accepting tough austerity terms for a bailout that expired June 30, they are alarmed at capital controls that have closed banks and rationed ATM cash.
They also overwhelmingly want to keep the euro.