International creditors demanded sweeping changes to Greek Prime Minister Alexis Tsipras’ tax and reform proposals on Wednesday, adding fresh uncertainty to talks aimed at unlocking aid to avert a debt default next week.

Sources close to the negotiations said the creditors had presented counter-proposals covering an array of differences on sensitive issues, hours before Euro Zone finance ministers were due to convene to try to approve an agreement.

Before flying to Brussels, Tsipras attacked the position of “certain” creditors — a swipe at the International Monetary Fund — as strange since he said they had rejected fiscal measures Athens put forward to plug a budget gap.

“This odd stance seems to indicate that either there is no interest in an agreement or that special interests are being backed,” the leftist premier tweeted.

Financial markets reacted nervously, with investors rushing into safe-haven German bonds and the euro suffering a brief sell-off. European shares dropped and US stocks opened lower.

A European Union official insisted the talks had not broken down and said the exchange of different proposals was a normal part of the negotiation.

But a Greek official said the lenders’ five page counter-proposal — full of crossings-out and underlining in red ink — differed little from their initial June 3 offer and took scant account of Athens' document. In Athens, an official in Tsipras' Syriza party said a state minister had branded the latest proposals “absurd” at a meeting of the party's political committee.

The talks were especially fraught because there is so little time left to reach a deal before Greece has to make a repayment to the IMF on June 30, the day its current bailout expires.

If Greece misses that payment and is declared in default to the IMF, it could trigger a bank run, capital controls and an eventual Greek exit from the euro zone, showing that membership of the currency is not irrevocable as its founders intended.

Among the many unresolved issues were labour laws, collective bargaining, pension reform, public sector wages, opening up closed professions, investment as well as value-added tax and corporate income tax.

Also in dispute were Tsipras' demands for debt relief, which euro zone partners do not want to address at this stage.

comment COMMENT NOW