Greek prime minister Alexis Tsipras will try to accelerate discussions on a Greek bailout when he meets EU leaders at a summit in Brussels on Wednesday, but EU sources have said a new proposal by Greece is "not acceptable".

Greece submitted revised bailout proposals to Brussels on Tuesday, which include new targets on a primary surplus. It also proposes that the ESM fund buy Greek bonds held by the ECB which mature in July and August as a way of cutting its debt burden.

However, EU officials poured cold water on the new Greek plan, pointing out that Greece was reopening discussions on the primary surplus that had already been agreed last Wednesday.

Mr Tsipras will come face to face with commission president Jean-Claude Juncker for the first time since the commission chief refused to take a phone call from the Greek prime minister on Saturday. At the G7 summit on Sunday, Mr Juncker strongly criticised Mr Tsipras's representation of the international lenders' position in an address to the Greek parliament on Friday .

Amid reports that the current bailout programme, which is due to expire at the end of this month, could be extended until next March, the Greek prime minister has urged his party to support him in the coming “crucial days” at a private meeting of Syriza in Athens.

Any agreement to extend the current bailout agreement, signed in February, would have to be agreed by the euro group. An extension would also have to address Greece’s immediate funding needs – the Greek government is not thought to have the funds to meet a bundled IMF payment of €1.5 billion due on June 30th.

European Commission vice-president Valdis Dombrovskis said a deal was possible. However he said on Tuesday Greece must agree on specific measures and primary surplus targets.

Meanwhile, in a speech in Berlin on Monday evening, Greek finance minister Yanis Varoufakis compared creditor demands on Athens to "hitting a sick cow to make it give more milk".

At the economic council of the ruling Christian Democratic Union in Berlin yesterday, Finland's new finance minister Alex Stubb said there were some EU finance ministers "whose patience is reaching an end".