Tunisia's political crisis has deepened after the assassination of a leading opposition figure.
The governing Islamist party refused to back its prime minister, who wants a non-partisan technocratic government.
Ennahda said Hamadi Jebali "did not ask the opinion of his party".
Protests after Chokri Belaid's death saw police fire tear gas at protesters in Tunis and in the central town of Gafsa. Unions have called for a general strike alongside his funeral on Friday.
In Gafsa demonstrators were observing a symbolic funeral outside the governor's office, throwing stones at the police.
Lawyers and judges across Tunisia have launched a two-day strike in response to Wednesday's killing, AFP news agency reports. Lawyers were seen among the protesters in Tunis on Thursday.
Earlier, four opposition groups - including Mr Belaid's Popular Front - announced that they were pulling out of the country's constituent assembly in protest.
The country's largest trade union, the General Union of Tunisian Workers, called a general strike for Friday. Meanwhile Tunisian state TV said universities had been ordered to suspend lectures on Saturday and Sunday.
France said it would close its schools in the capital Tunis on Friday and Saturday.
Mr Belaid's killing has brought to a new pitch a long-simmering political crisis in Tunisia, with secularists and liberals accusing the Islamists of amassing too much power, the BBC's Sebastian Usher says.
Ennahda denies opposition claims that it was behind the assassination in Tunis.
"We in Ennahda believe Tunisia needs a political government now," party Vice-President Abdelhamid Jelassi said on Thursday.
"We will continue discussions with others parties about forming a coalition government," he added.
Ennahda spokesman Abdelhamid Aljallasi later added that party members had not been informed of the prime minister's decision before he announced it.
Late on Wednesday, Mr Jebali said he would dismiss the current cabinet and form a government of "competent nationals without political affiliation".
The new ministers would have a mandate "limited to managing the affairs of the country until elections are held in the shortest possible time", the prime minister said in a nationally televised address.
The killing of Mr Belaid - the first political assassination in Tunisia since the Arab Spring uprising in 2011 - sparked angry protests across Tunisia.
He was shot dead at close range on his way to work. The attacker fled on the back of a motorcycle.
Thousands of people later rallied outside the interior ministry, many chanting slogans urging the government to stand down and calling for a new revolution.
In the centre of Tunis, a police officer was killed during clashes between police and opposition supporters protesting against Mr Belaid's death.
Mr Belaid was a respected human rights lawyer, and a left-wing secular opponent of the government which took power after the overthrow of long-serving ruler Zine el-Abidine Ben Ali.
Current President Moncef Marzouki said the assassination should not affect Tunisia's revolution.
"There are many enemies of our peaceful revolution. And they're determined to ensure it fails," he said.
Referring to Mr Belaid as a "longstanding friend", he said his "hateful assassination" was a threat.
"This is a letter being sent to us that we will refuse to open," the president said.
Mr Marzouki also announced that he was cutting short a visit to France and cancelling a trip to Egypt to return home to deal with the crisis.