Former Parti Quebecois leader Andre Boisclair announced his departure from politics on Monday.

Boisclair will give up his seat as MNA for Pointe-aux-Trembles on Nov. 15 -- two years to the date that he assumed his duties as PQ leader.

Boisclair, 41, informed Pauline Marois of his decision on Sunday afternoon saying it was time to take on new challenges such as the development of Quebec's economic sustainability.

In a written statement in French, Boisclair thanked his constituents and members of his party saying his time in politics was "demanding" but also very rewarding and that he is leaving public life with a sense of accomplishment.

He said his last 18 years in politics were peppered with "great moments" and tough decisions, and that he has no regrets.

Reaction from his constituents was mixed on Monday.

"He was not appreciated by people in his party, so I think it's a good decision for him, but I regret that," a resident of his former riding told CTV Montreal.

Boisclair resigned as head of the PQ six weeks after the party experienced one of its worst provincial elections last March, finishing in third place with 36 of 125 seats.

Marois, a longtime party stalwart, became PQ leader by acclamation in late June when no other candidate emerged to challenge her nomination.

A career politician, first getting elected at age 23, Boisclair had been a cabinet minister in the PQ governments of Lucien Bouchard and Bernard Landry.

After the 2003 provincial election, Boisclair studied at the prestigious John F. Kennedy School of Government at Harvard University.

He was going to take a job in the corporate sector in Toronto when Landry quit as party leader in 2005.

Boisclair bested Marois to take the leadership.

He did so even though he admitted to using cocaine during the years he served as a cabinet minister between 1996 and 2003.

The openly gay Boisclair raised questions about his judgment and maturity when he appeared in a parody of "Brokeback Mountain" featuring actors wearing the masks of Prime Minister Stephen Harper and U.S. President George Bush.

Many hardline sovereigntists saw him as being too soft on the sovereignty agenda. In kicking off the provincial election campaign, Boisclair promised a "public consultation" on sovereignty and avoided the word "referendum."

While he was seen to have run a reasonably good campaign, Boisclair, a Montrealer, didn't connect with rural and small-town francophone Quebec in the way that ADQ Leader Mario Dumont did. Dumont's party -- which believes in more "autonomy" for Quebec, but won't support a referendum -- won 41 seats, up from four in 2003, making it the official opposition.

With files from CTV's Tania Krywiak and The Canadian Press