Tsipras to SYRIZA MPs: It will be hard for me to be PM without your support

While acknowledging their objections to the extremely harsh austerity demanded, he urged them not to let the measures pass with the support of the opposition alone.

Tsipras underlined that he was prime minister because there was a Parliamentary Group on which he could rely and depend. If he did not have this support from this Parliamentary Group, Tsipras said he would find it hard to be prime minister on the following day - to thunderous applause from the MPs below.

Earlier, the prime minister had also addressed the issue of whether he had been right to accept the ultimatum presented by Greece's Eurozone partners:

"One thing we must discuss is whether the dilemma presented to the Greek government between [this] agreement or Grexit was real or fake," he said, urging anyone who believed that he had been misled by a bluff or false dilemma to say so.

"If someone believes that this threat was real, however, then he must also consider the consequences of non-agreement," he then pointed out.

According to the same sources, Tsipras then turned to the issue of Greece's alternatives and said that the only alternative on offer was to accept plan presented by the German Finance Minister Wolfgang Schaeuble for a "consensual Grexit", as expressed by the MP Costas Lapavitsas.

He pointed out, however, that Schaeuble's plan also had a second element, which was to topple the government.

"Neither of these two outcomes is going to happen," Tsipras said, ahead of the crucial vote on Wednesday night that may well mark the disintegration of the ruling coalition and his government.

Passage of the omnibus bill being fast-tracked through Parliament, legislating for a raft of austerity measures and tax hikes demanded by Greece's creditors in order to start talks on a 3rd bailout, is essentially assured with the backing of the mainstream opposition parties New Democracy, PASOK and Potami.

Less certain, however, is how many within ruling SYRIZA will give their backing, after open revolt by both ministers and MPs. The wager for Tsipras now is whether he will be able to maintain sufficient cohesion within his party to allow him to weather the difficult days ahead, when his government must conclude an agreement with the country's Eurozone partners and lenders.