Tunisia’s Prime Minister Ali Larayedh resigned on Thursday as part of a plan to end months of political deadlock, amid a fresh eruption of social unrest.

Tunisia's Prime Minister Ali Larayedh resigned on Thursday as part of a plan to end months of political deadlock, amid a fresh eruption of social unrest.

His resignation sees the departure of Tunisia's first democratically elected government, which came to power after Zine El Abidine Ben Ali was overthrown in the first of the Arab Spring uprisings almost three years ago.

"We took on our responsibilities in very difficult conditions. We have worked for the benefit of our country and we respect our commitments," Larayedh said on national television, before announcing his resignation at a press conference.

His stepping down comes as part of a blueprint, drawn up by mediators, to put the democratic transition back on track after the assassination of opposition MP Mohammad Brahmi by suspected militants last year.

Under the plan, he is to be replaced within 15 days by premier designate Mehdi Jomaa at the head of a government of technocrats that will lead the country to fresh elections this year under a new constitution.

"The president has charged me with supervising the running of the country until the new government of Mehdi Jomaa is formed," Larayedh said.

Larayedh's Ennahda party has been under mounting pressure to relinquish the grip on power it won after the uprising in elections to a constituent assembly, as the economy has stagnated and social unrest has intensified.

The formation late Wednesday of an independent authority to oversee fresh elections, which the Islamist part had set as a condition for stepping down, removed the last hurdle to Larayedh's resignation, according to the powerful UGTT trade union confederation, the main mediator in the crisis.

The approval of a new constitution, which Ennahda had also demanded in return for handing over power, is on track to meet an agreed deadline of January 14, the uprising's third anniversary, with the assembly voting on it intensively article by article.

The new charter had been delayed for months by the withdrawal of opposition assembly members in protest at Brahmi's killing in July.

On Thursday, the constituent assembly agreed to an article setting a goal of 50-50 representation between the sexes in all elected bodies, an exceptional move for the Arab world but one in keeping with the secularism that Tunisia adopted at independence which has given its women by far the most extensive rights in the region.