An unprecedented war of words has broken out between Greece's outgoing government, the Parliament chief and the President over early elections likely to be held on September 20.
The government of Prime Minister Alexis Tsipras has accused parliamentary speaker Zoe Constantopoulou of "behaving like a dictator" after she branded the early election procedure "undemocratic and unconstitutional."
Tspiras resigned on Thursday, going on the offensive to defend the tough terms he accepted in the 86-billion-euro ($96 billion) rescue package which had triggered a rebellion in his radical-left Syriza party.
The mutiny scuppered his parliamentary majority and last week 25 of the rebels broke away to form a rival group called Popular Unity.
The head of state, President Prokopis Pavlopoulos, is expected to name a caretaker government on August 28.
Under the constitution, Pavlopoulos is obliged to invite the largest opposition parties to attempt to form a government before formally setting a date for elections.
The conservative New Democracy party was on Friday given a three-day exploratory mandate.
The breakaway Syriza rebels will be next in line on Monday.
The procedure has no chance of success, as neither group can muster enough lawmakers for a parliamentary majority in the 300-seat chamber.
But Constantopoulou has accused the president of breaking the rules by skipping a parliamentary technicality in order to hasten the procedure.
Late on Saturday, the president responded by dismissing her arguments as "legally baseless".
Constantopoulou, whose father was a former head of Syriza, vehemently opposed the third EU bailout Tsipras signed on July 13 and repeatedly sought to frustrate its ratification through stalling tactics.
As a result, three successive parliamentary votes on the bailout were held overnight, and were concluded narrowly before deadlines set by Greece's creditors expired.