Talks aimed at reaching an 11th-hour deal between Greek ministers and their bailout creditors collapsed on Sunday evening after a new economic reform proposal submitted by Athens was deemed inadequate to continue negotiations.

The breakdown is the clearest sign yet that differences between the two sides may be too wide to breach, increasing the possibility that Athens will not secure the €7.2bn in bailout aid it needs to avoid defaulting on its debts — including a €1.5bn loan repayment due to the International Monetary Fund in just two weeks.

Greek negotiators, including Nikos Pappas, aide-de-camp to Alexis Tsipras, the Greek prime minister, left the headquarters of the European Commission only 45 minutes after entering the building for what were characterised as a “last try” by one of the eurozone officials involved in the talks.