AFP/Athens

Greece faced deepening scepticism ahead of talks on Monday on its plans for reforms to secure a financial lifeline as Athens warned of a possible referendum if its proposals are rejected.

Finance Minister Yanis Varoufakis said "there could be problems" if his colleagues from the 19-country eurozone do not accept the list that he is due to present at the Eurogroup meeting in Brussels.

"We can go back to elections. Call a referendum," Varoufakis warned in an interview with Italian newspaper Corriere della Sera on Sunday. "But, as my prime minister told me, we are not glued to our seats yet."

The Greek measures include plans to streamline bureaucracy, raise revenue from online gambling and, in a widely derided suggestion, hire any army of amateur tax sleuths -- including tourists -- to help clamp down on tax dodgers.

But Eurogroup chief Jeroen Dijsselbloem, to whom Varoufakis sent the proposals in an 11-page letter on Friday, said that Greece's reform plans were "far from complete".

"The Greeks know this. It's a difficult process that's going to take a long time," he told a panel discussion in Amsterdam on Sunday.

The list must also be discussed with the European Central Bank (ECB) and International Monetary Fund (IMF), the other members along with the EU of the "troika" of Greece's creditors, a member of Dijsselbloem's entourage said.

- 'Fewer words, more action' -

Varoufakis later said the comments had been taken out of context but they risk causing further irritation at home and abroad at the hard-charging style of the shaven-headed, Burberry scarf-wearing "rock star" former economics professor.

"We will find a solution. Building up scenarios to the contrary is pointless," Greek Deputy Budget Minister Dimitris Mardas said Monday when asked about the referendum comments.

Dimitris Vitsas, an official from the hard-left Syriza party of new Prime Minister Alexis Tsipras, told Greece's MEGA television: "Neither elections nor a referendum are on the table. We are going to the Eurogroup to seal a deal on the base of a popular mandate, which is not to back down."

Tsipras told Varoufakis and other ministers at the weekend to give fewer interviews, urging "fewer words and more action".

The last time Greece threatened a referendum on its bailout in November 2011, it sent global markets into panic, infuriated its European partners and led to the fall of then prime minister George Papandreou.

Eurozone ministers agreed at a meeting on February 20 to extend Greece's current bailout by four months until the end of June, but the payout of the next tranche of some seven billion euros at the end of April is dependent on its partners accepting the reform plans.

- 'Serious' situation -

Greece has had two EU-IMF bailouts worth 240 billion euros ($260 billion) since 2010 to stave off bankruptcy and keep the country in the euro, in exchange for widely-loathed austerity measures.

But Tsipras, who won elections in January, has caused alarm in the eurozone by vowing to renegotiate Greece's debt and abandon much of the austerity.

European Commission chief Jean-Claude Juncker warned of the need to recognise the gravity of the situation in Greece, both for its citizens and the wider risks to the eurozone.

"We must be sure that the situation does not continue to deteriorate in Greece. What worries me is that not everyone in the European Union has understood how serious the situation is," Juncker told German paper Die Welt.

With reports last week of officials looking at borrowing money from state pension funds and EU farm subsidy payments to meet the country's huge debts, the Greek daily Kathimerini warned of "internal bankruptcy".