Greece has told its creditors it cannot implement some of the extra changes required in exchange for fresh bailout loans.

In a letter sent to the European Commission, the European Central Bank (ECB) and the International Monetary Fund (IMF) last week, finance minister Euclid Tsakalotos said some of the additional demands could not be fulfilled.

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The existence of the letter, first revealed by Greek media and Reuters, was confirmed to EUobserver.

It could further delay disbursement of much-needed funds to pay off IMF loans expiring in June and European Central Bank bonds maturing in July.

After months of negotiations, Greece and its lenders last week agreed on the disbursement of €10.3 billion in two tranches, in mid-June and in September, under the condition that Athens amended laws concerning pensions, privatisation and sale of non-performing loans.

In the marathon talks they also agreed to open the way for debt relief, something Greece has been keen to secure.

There are two problematic issues for the Greek government.

It said it cannot axe aid for small pensions, as required by creditors. It also wants to exempt loans with a state guarantee from the loan sale scheme.

Greek daily Kathimerini reported that the governement initially hoped to complete all the necessary changes before the ECB’s governing council meets on Wednesday (1 June).

The new target to complete the necessary actions has been moved to Friday.