The Tsipras government has told the International Monetary Fund that it will delay the first of four debt repayments due in June.

The €300m payment is due today and Athens will now have to pay €1.5 billion ($2.2 billion) in total by 30 June – the date on which its bailout deal with the EU and IMF runs out.

Greece is trying to reach a deal to unlock the final tranche of bailout funds worth €7.2 billion ($10.5 billion), but the IMF, European Union and European Central Bank say significant differences remain between the two sides.

An IMF spokesman said that under a precedent dating back to the 1970s, governments could ask to amalgamate “multiple principal payments falling due in a calendar month … to address the administrative difficulty of making multiple payments in a short period”.

The last country to bundle together IMF debt repayments was Zambia in the 1980s.

After talks in Brussels this week Prime Minister Tsipras reiterated that an agreement with Greece’s international creditors was “in sight”.

However, head of the eurozone’s finance ministers Jeroen Dijsselbloem described the gap as being “still quite large”.

Tsipras rejected proposals put forward this week by Greece’s creditors in talks with Mr Dijsselbloem and European Commission chief Jean-Claude Juncker.

The key sticking point relates to ‘primary budget surpluses’ – the amount by which tax revenues exceed public spending. Athens wants lower primary budget surplus targets.

International creditors have asked for pension cuts, a reduced civil service, VAT reform, fewer tax rebates and more private sector investment.

The Syriza leader described such actions as “points that no-one would consider as a base for discussion.”

Greece has presented a 47-page plan on how to overhaul its economy without resorting to harsh austerity measures. Tsipras has said that Greece’s reform proposals “remain the only realistic plan on the table.”

Any eventual deal between the creditors and the government would have to be approved by the Greek parliament, and could even be derailed by Syriza’s radical left wing.

Tsipras is under pressure to reject any plan that would deliver public service cuts and further tax hikes, with some Syriza officials saying they would rather hold snap elections than be forced to deliver more austerity measures.

As the postponement of the IMF repayment was announced, Greek Finance Minister Yanis Varoufakis took to twitter, inviting German Chancellor Angela Merkel to Greece to deliver a message of hope.

“She could use the opportunity to hint at a new approach to European integration, one that starts in the country that has suffered the most, a victim of both the eurozone’s monetary design and of its society’s own failings,” he wrote.

“Hope was a force for good in post-war Europe, and it can be a force for positive transformation now.”