Greek finance minister Vassilios Rapanos quits before he started in the job

Greece will enter Thursday's critical European summit in a state of disarray after its Finance Minister-designate resigned over health problems yesterday.

Vassilios Rapanos, the former head of the Bank of Greece, has been in hospital since Friday with stomach pains. The nature of his illness was not officially confirmed but it is known to be serious.

He quit in a letter to the new Prime Minister, Antonis Samaras, who is recovering from eye surgery, and surprised most observers when he confirmed he would not be travelling to Brussels for the summit. Mr Samaras has instead left the task of wringing bailout concessions – which include more time to meet fiscal targets – to a delegation led by the new Foreign Minister. Greece's eurozone partners are already frustrated by political deadlock in Athens which has left the nation rudderless for two months while the financial crisis has deepened.

The departure of Mr Rapanos, left, who did not last long enough to be sworn in, will leave the responsibility for Greece's talks in the hands of George Zanias, the Finance Minister in the interim government. The econometrics professor, who has been one of the country's key negotiators during the past two years of bailout talks, is also in poor health after being hospitalised with chest pains during an EU summit in October.

Athens's ailing politicians have delayed an inspection by the EU, the IMF and the European Central Bank – without which the next loan payments cannot be made. The new government must also pass more than €11bn (£9bn) in fresh cuts before the end of June.