'We will win' says Tsipras as Greece vote goes down to wire

Tsipras declared his victory would strike a blow for Europe's left, as final polls gave him a slim lead

Alexis Tsipras wound up his campaign to be re-elected Greek prime minister by declaring his victory would strike a blow for Europe's left, as final polls gave him a slim lead.

The return of his Syriza party to power after tomorrow's vote would deliver "a key message for Europe", Tsipras told thousands of supporters in his last electoral rally in Athens.

"Do we want a Europe of austerity or one of solidarity and democracy? The result (of the vote) will be a key message for Europe," he said.

Flanked by the leader of Spain's anti-establishment Podemos, Pablo Iglesias, and other EU radicals, the charismatic 41-year-old slammed the conservative leaders of Germany and Spain.

"The struggle to change Europe continues," he said, hailing those who are sheltering migrants fleeing war and persecution.

But as thousands of mostly young supporters turned out on a hot Athens night for the rally, Tsipras's flamboyant ex-finance minister Yanis Varoufakis said he would be voting for Eurosceptic radicals who have broken away from Syria.

Tsipras, in a white shirt and with his sleeves rolled up, said that on "Sunday we will sweep away the old", an apparent reference to his main rivals for government office, the established conservative New Democracy party led by Vangelis Meimarakis.

The vote would show, he added "if the old system that governed for 40 years is going to return or if we are going to take a step forward.

"The people will say no to this old system of corruption, no to the enshrining of the oligarch establishment."

Tsipras won office in January with 36.3% of the vote on an anti-austerity ticket, but then upset supporters in July with a U-turn cash-for-reforms deal with Greece's international creditors despite winning a huge "No" vote in a referendum on the issue.

But even after the broken promises, many voters believe he has their interests at heart -- a break with past leaders they perceived as corrupt and linked to powerful interests.