* General strike held in protest at lawyer's murder
* Widow applauds protesters for defending democracy
* Prime minister's plan for caretaker government foiled
By Tarek Amara
TUNIS, Feb 8 (Reuters) - Tunisia's political crisis looked likely to deepen on Friday with strikes and protests planned around the funeral of assassinated opposition politician Chokri Belaid.
Belaid's killing on Wednesday has brought thousands of people onto the streets of the capital Tunis and other cities in violence-marred protests.
Unions have called a general strike for Friday, setting the stage for further confrontation two years on from the pro-democracy revolution that inspired the Arab Spring.
Tunisia is riven by tensions between the dominant Islamists and their secular opponents, and by disillusionment over the lack of social progress since the overthrow of dictator Zine al-Abidine Ben Ali in January 2011.
In response to Belaid's assassination, Prime Minister Hamdi Jebali, an Islamist, said on Wednesday he would dissolve the government, name a non-partisan cabinet of technocrats and hold early elections. But his partners opposed the move and it is yet to be approved by parliament.
No one has claimed responsibility for the killing of Belaid, a lawyer and secular political figure, who was shot by a gunman as he left home for work on Wednesday.
But a crowd set fire to the headquarters of Ennahda, the Islamist party of Prime Minister Jebali, who leads a coalition with two junior secularist parties. Ennahda denies any involvement.
While Belaid had only a modest political following, his criticism of Ennahda policies spoke for many Tunisians who fear religious radicals are bent on snuffing out freedoms won in the first of the revolts that rippled through the Arab world.
"Criminals assassinated Chokri's body, but will not assassinate Chokri's struggle," his widow Besma said on Thursday.
"My sadness ended when I saw thousands flocking to the streets...at that moment I knew that the country is fine and men and women in my country are defending democracy, freedom and life."
All three ruling parties and sections of the opposition rebuffed Jebali's plan to create a small, technocrat government to take over day-to-day matters until elections could be held, demanding they be consulted before any such move.
"In the likely event that there is no agreement, civil unrest will increase, reaching a level that cannot be contained by the police," said Firas Abi Ali of the London-based Exclusive Analysis think-tank.
"If unrest continued for more than two weeks, the army would probably reluctantly step in and back a technocrat government, as well as fresh elections for a new Constituent Assembly."
The economic effect of political uncertainty and street unrest could be serious in a country which has yet to draft a post-revolutionary constitution and which relies heavily on the tourist trade.
The cost of insuring Tunisian government bonds against default rose to its highest level in more than four years on Thursday and ratings agency Fitch said it could further downgrade Tunisia if political instability continues or worsens.
(Writing by Robin Pomeroy; Editing by Angus MacSwan)