Greece's leftist government will be able to push through a crucial pension change in parliament, one of the measures the country has agreed to under its international bailout, the deputy prime minister said in a newspaper interview released Saturday.

Greece has drafted a proposal to overhaul its ailing pension system, which envisages merging all six pension funds into one and a possible cut of future main pensions by up to 30 percent. It plans to submit the proposal to parliament by the end of the month and to hold a vote on it in early February.

Prime Minister Alexis Tsipras's government has a parliamentary majority of just three seats, and the pension overhaul, which opposition parties and many pensioners and workers oppose, will test its resolve to implement actions agreed with international creditors.

Asked whether Tsipras' coalition has secured enough support from lawmakers for the bill, Deputy Prime Minister Yannis Dragasakis said in an interview with Avgi newspaper: "The government has a strong and solid majority."

"But passing the relevant law won't be enough," he said, adding that the government should also secure backing from workers and political parties to implement the changes.

Hundreds of Greek pensioners and workers marched in central Athens Friday to protest against the plan, which is part of a package Athens needs to implement to conclude the first review of its 86 billion euro ($93.4 billion) bailout and start debt relief talks. Greece pension protest, Athens 1/8/16 Protesters from the communist-affiliated trade union PAME pass through a riot police cordon during a demonstration against the government's pension bill in Athens, Jan. 8, 2016. Photo: REUTERS/Alkis Konstantinidis

A representative of the country's international lenders said Saturday that the review could be wrapped up within a reasonable time frame as long as Greece stuck to its promised program.

"The Greek government demonstrated a certain degree of commitment to delivering on its mandate to implement the Memorandum of Understanding which was agreed last August with the other euro area governments," the ECB's Monetary Policy Strategy division head Rasmus Rueffer said in an interview with Proto Thema newspaper.

"I trust that this commitment prevails and that the first review will be concluded within a reasonable time frame."

Rueffer said the ECB would consider reinstating a waiver of Greek bonds, which would mean letting Greek banks again swap their country's government bonds for ultra-cheap ECB funding, and including the securities in the eurozone's central bank bond purchasing scheme "once the conditions are right."

He also said the International Monetary Fund's full participation in the Greek program would "be highly desirable."

The IMF said last year it would wait to see the outcome of Greece's debt relief talks with EU partners before agreeing to inject new cash as part of the bailout program. Tsipras last month accused the fund of making unrealistic demands, but eurozone officials have ruled out the fund's exclusion from the bailout.

As Greece seeks support at home and in Europe, Finance Minister Euclides Tsakalotos met Italian Economy Minister Pier Carlo Padoan on Friday in Rome to discuss the timetable for completion of the first review and debt reprofiling.

He discussed investments, unemployment and the banking union with his Portuguese counterpart Mario Centeno on Saturday, a Greek Finance Ministry official said.

Greece's mountain of debt is expected to reach 187.8 percent of annual gross domestic product this year.

Dragasakis said the Greek debt issue is a European problem that should be mutualized. But if European leaders were reluctant to consider a radical solution at this point, then Greece should seek "a temporary solution, which will make sure that debt and its servicing expenses will not hinder long-term borrowing, investment and social policies, as it is the case now," he said.

Rueffer said the eurozone partners have made clear that a nominal debt "haircut" was not an option. However, there was room for an extension of maturities and grace periods, he said.