Tunisia’s ruling Islamists and opposition were to begin hard-won negotiations on Wednesday to end months of political deadlock, with Prime Minister Ali Larayedh expected to announce his government’s resignation.

Tunisia's ruling Islamists and opposition were to begin hard-won negotiations on Wednesday to end months of political deadlock, with Prime Minister Ali Larayedh expected to announce his government's resignation.

Hundreds of opposition protesters gathered in central Tunis by early afternoon to keep up the pressure on the government, amid a heavy police presence, shouting slogans such as: "Government of traitors, resign!"

But the crowd was smaller than the tens of thousands who gathered in August demanding the resignation of the Islamist-led coalition, while a separate pro-government protest called by the League for the Protection of the Revolution failed to materialize.

Larayedh was due to convene an extraordinary cabinet meeting before the talks and make a statement at around 1330 GMT, his office said.

Parliament speaker Mustapha Ben Jaafar said he expected the premier to announce his commitment to resign, allowing negotiations between Tunisia's bitterly divided factions to end the political paralysis gripping the country since the July killing of opposition MP Mohamed Brahmi.

"In principle, the government will announce its commitment to respecting the roadmap and its resignation within a few weeks," he said in a televised interview on Tuesday evening.

Larayedh has previously stated that he would step down only once a new constitution has been adopted, in line with the roadmap drawn up by mediators and agreed to earlier this month by his ruling Islamist party Ennahda.

Some 60 opposition MPs who have been boycotting parliament since the political crisis erupted also said they had received assurances the national dialogue would begin with Larayedh announcing a "clear commitment" to step down.

According to the political roadmap, the talks will lead within three weeks to the formation of a new caretaker cabinet of technocrats.

Negotiators will also have one month to adopt a new constitution, electoral laws and a timetable for fresh elections, key milestones in the democratic transition which has effectively been blocked by wrangling between the Islamists, their coalition allies and the opposition.

Seven Tunisian policeman were killed Wednesday in clashes with a group of militants in the central Sidi Bouzid region, state television reported, citing security sources.

Tunisian opposition activists shout slogans as they hold portraits of assassinated opposition figures Mohamed al-Brahmi (left) and Chokri Belaid during a demonstration in Tunis, on October 23, 2013

The fighting broke out when the National Guard tried to raid a house in the locality of Sidi Ali Ben Aoun where the gunmen were holed up.