Premier Jean Charest is losing one of the most important members of his cabinet and the man responsible for keeping the Liberal troops in-line.

On Monday, Public Security Minister Jacques Dupuis announced that he is leaving politics.

During his twenty years in the business, he has overseen a number of major portfolios.

Now, he says it is time for him to move on – though he is not yet sure to what.

Dupuis has come under fire in recent years - first over the handling of a public inquiry into the shooting of a Montreal teen in 2008; then he was linked to Luigi Coretti, a bankrupted security firm owner with controversial ties to the government.

In addition, the Charest government has been battered by scandals over questionable fundraising practices and allegations of influence-peddling.

Still, Dupuis insists that his decision has nothing to do with such matters.

"My decision is a personal decision based on personal reasons has nothing to do with politics," he says. "Being the leader of the government, I was used to being criticized. [] Politics is an extreme sport"

Dupuis notes that his job has meant frequently working seven days a week, as much as 18 hours per day.

At age 61, he feels he is ready for something else and that it has taken months of reflection to come to that conclusion.

As for Premier Jean Charest, at Dupuis' side for the announcement, he sounded choked up when discussing the departure.

"This touches me personally because he is a friend," Charest said.

Dupuis' resignation leaves the door open to a cabinet shuffle that has been rumoured since June.

The premier will also call a by-election to fill Dupuis' seat in St-Laurent, a district he has represented for 12 years.

The man who will run under the provincial Liberal banner is a well-known face.

As Dupuis was announcing his departure, Jean-Marc Fournier was on-hand to speak of his planned return to Quebec politics after serving as a top aid to federal Liberal Leader Michael Ignatieff.

Fournier served in the Charest cabinet until 2008 and is expected to become a senior minister in the Quebec government.

With files from The Canadian Press