TUNIS (Reuters) - Tunisia's Prime Minister on Monday proposed holding fresh elections in December, and said that the Islamist-led transitional government would go on with its work despite mounting efforts to dissolve it.

Ali Larayedh accused the secular opposition, which has launched widespread protests against the ruling Islamist Ennahda party, of being "coupists".

"The government will continue performing its duties and it will not abandon them, not because it is keen to hold power, and we will maintain our responsibilities until the final moment," he said in televised speech.

"We will focus on holding the elections by the end of this year and our date is December 17."

The date is symbolic - it was the day in 2010 when vegetable vendor Mohamed Bouazizi set himself on fire in an act of protest, triggering demonstrations in 2011 that toppled Tunisia's autocratic ruler Zine al-Abidine Ben Ali. They also inspired other uprisings across the Arab world.

The prime minister promised free and transparent elections and said international observers would be welcome.

Tunisia once seemed a model for democratic transition among countries that have undergone similar upheavals. But it is now struggling to overcome divisions over the Ennahda-led government and, more critically, the transitional Constituent Assembly that is only weeks away from completing a draft constitution.

(Reporting by Tarek Amara; and Erika Solomon; Editing by Mike Collett-White)