In a huge blow to the new government spearheaded by Prime Minister Antonis Samaras, Greek Finance Minister Vassilis Rapanos resigned citing ill health, just a few days after the elections.
Rapanos, 65, who is currently the head of the National Bank of Greece, was taken to hospital on Friday for nausea and dizziness.
"The recent incident that led me to being hospitalised indicated that my health problem has not been overcome. Following discussions that I had with my doctors, I have concluded that the condition of my health, for the time being, is not what it should be in order to fulfil my duties adequately," Rapanos said in his resignation letter, quoted the Greek Reporter.
He could not be sworn in with other ministers on 21 June and has a history of ill-health, according to reports.
Doctors said the results of the medical tests were normal and Rapanos would be discharged on Tuesday.
However the resignation has come at crucial time for Greece as it teeters on the brink of economic disaster and exit from the euro currency.
Samaras, who is himself hospitalised after an eye surgery, faces a difficult task finding a qualified substitute for Rapanos to deal with the growing unemployment and deepening economic crisis.
If he had taken up the job, Rapanos, would be one of the key negotiators from Greece in the bailout talks with European nations in Brussels on Thursday.
Greece was given a €130 billion euro rescue by the single-currency bloc and the new coalition government wants to ease the bailout conditions citing lenient terms of Spanish banks' subsequent bailout.
Pasok leader Evangelos Venizelos, who was finance minister when the €130bn (£104bn) rescue package was agreed, has called renegotiation of the deal a "national priority" with Athens announcing a list of steps to soften the impact of accord over the weekend. "These unexpected illnesses couldn't come at a worse time. We need the strongest team possible to revise the memorandum," said one government source.
The heat is already on. Leading EU figures, starting with the German finance minister Wolfgang Schäuble, have announced that Greece is way off-track in its reform programme.
At the two-day meeting with EU officials, outgoing finance minister during the caretaker government George Zanias is expected to represent Greece.
Names from various political parties including New Democracy are doing the rounds for replacement.