Greek Prime Minister Alexis Tsipras struggled to contain opposition from within his party ahead of a vote Wednesday on the second set of reforms demanded by international creditors. The vote will decide if Greece can enter talks to receive the next round of critically needed bailout funds.

Tsipras on Tuesday condemned disgruntled lawmakers within his ruling Syriza party who are opposed to austerity measures demanded by Greece's international creditors, including the International Monetary Fund (IMF), accusing them of "hiding behind the safety of my signature," the BBC reported.

"Up until today I've seen reactions, I've read heroic statements but I haven't heard any alternative proposal," Tsipras said, calling on his party to respect the will of the country's citizens. "Syriza as a party must reflect society, must welcome the worries and expectations of tens of thousands of ordinary people who have pinned their hopes on it."

Unless Greece manages to secure another deal for bailout funds from its creditors -- which also include the European Central Bank and the European Commission -- the country faces the possibility of a default and could be forced to leave the eurozone, or what's been dubbed as a "Grexit."

The creditors have called for new European Union-mandated rules that would prop up failing banks, but do not include previous reforms that creditors had pushed for, such as pension cuts to discourage early retirement and raising taxes on farmers. Those reforms are reportedly set to be negotiated in detail later.

The negotiations for a fresh round of bailout funds come after Greek voters rejected previous bailout terms in a July referendum. However, despite voting against the austerity measures imposed by its creditors, Athens later agreed upon a bailout package that included more severe pension cuts and tax increases than the one previously discussed.

A vote last week on structural reforms and budget cuts, demanded before new bailout talks could resume, passed in the Greek parliament but was rejected by 39 Syriza lawmakers who refused to vote for the deal, exposing a rift within the left-wing Syriza party, which was elected in January for promising a tough stance against austerity.

"It is ideological, political and strategic default for Syriza," former Syriza lawmaker Rudi Rinaldi said, while resigning from the party's 13-member political committee.

Also on Tuesday, a senior German lawmaker warned ahead of the vote that Athens should not backtrack on its agreements. 

"We are keeping a close eye on whether Athens not only adopts the reforms, but also implements them," Gunther Krichbaum, chairman of the German parliament's Europe committee, told the newspaper Bild, as cited by Ekathimerini. "Greece must fulfill the conditions, otherwise the money cannot flow."

Meanwhile, Greece's economy continues to flounder. After talks with creditors started to break down in January, economists have gone from predicting 2 percent growth for 2015 to a 0.7 percent contraction for the country's economy, according to a Bloomberg survey. And over a quarter of the country's workforce remains out of a job, with youth unemployment at nearly 50 percent.

Officials from Greece's creditor institutions are due to meet in Athens on Friday to discuss further bailout terms with the government.