OTTAWA -  

Bloc Quebecois MP Louise Thibault announced Thursday she is quitting the sovereigntist party, saying she felt her views were not respected by leader Gilles Duceppe.

Thibault, who has represented the riding of Rimouski-Neigette-Temiscouata since 2004, said she will sit as an Independent. A former federal bureaucrat, she had been the party's critic on public works and government services.

"My right to speak my mind and my right to think differently is not something recognized or valued,'' Thibault said in an interview. "I was disappointed that Gilles Duceppe, among others, had this closed and intransigent attitude toward me.''

Thibault specifically cited last year's vote on same-sex marriage as a sore point between her and Duceppe. Duceppe threatened Bloc MPs with sanctions if they did not vote against reopening debate on the issue.

Thibault said she remains a sovereigntist.

Bloc colleague Louis Plamondon said he felt Thibault was not at ease with how a political party operates.

He said the Bloc caucus always spends a long time debating serious issues until a consensus is reached, and Duceppe does not dictate the outcome.

"Duceppe is demanding,'' Plamondon said. "After a debate has taken place, he demands that we stick to the consensus that was reached.''

Thibault makes four MPs the Bloc has lost this session.

Michel Gauthier announced earlier this month he was leaving for health reasons; Yvan Loubier ran unsuccessfully for the Parti Quebecois; and Benoit Sauvageau died in a car accident last summer.

Duceppe, the longest serving leader in the Commons, has faced a tough political season.

The Bloc Quebecois' polling numbers have been sagging and political cousins the Parti Quebecois came in third in the Quebec provincial election.

Duceppe had been rumoured to be contemplating a run for the helm of the PQ, but current leader Andre Boisclair has said he will be staying put.