New Brunswick Justice Minister Michael Murphy has resigned suddenly from cabinet, a week before the legislature returns to continue debate on the Liberal government's contentious plan to sell NB Power to Hydro-Québec.

The two-term Moncton North MLA confirmed the resignation in a statement released Monday and told reporters at an afternoon news conference that he made his decision so he could spend more time with his family and return to practising law.

"There are no other reasons other than it is the time to move on, to return to my practice and my family," Murphy said.

"There are no legal issues of any nature whatsoever so that should be clear."

Murphy will keep his seat in the legislative assembly for the next five weeks to allow for the "completion of constituency work."

However, Murphy will leave the legislative assembly before a final vote is taken on the controversial decision to sell NB Power to Hydro-Québec.

"I think the people need to understand that the NB Power sale is something that is not yet complete, that the premier has more to say on that in the coming weeks and I support this government," Murphy said.

"The premier will have more to say, the MOU is a work in progress."

In a statement, Premier Shawn Graham said he accepted Murphy's resignation with "deep regret."

"This is not an easy decision for him to make, but one which he must make for the best interests of himself and his family," Graham said.

"He has been a valued colleague and an active and engaged minister and MLA who has always put the interests of his constituents and New Brunswickers first."

Graham said he didn't try to persuade Mike Murphy to stay in politics because it wouldn't have been right to try to change his mind.

"I wrestled with that as premier. You know, do I sit down and try to convince him to stay on longer? But, ultimately, that would be doing a disservice to his family," Graham said.

"And that's his priority today, and he's been clear. After the Christmas break, you have time to put things into context. And Mike today is putting his family first, and I truly do respect that."

Murphy and Graham both said the decision has nothing to do with the controversy over the sale of NB Power to Quebec.

Under the province's Elections Act, a byelection must be called within six months of a vacancy being declared in the legislative assembly.

Murphy's decision to wait to resign his seat for five weeks would mean the byelection would occur in mid-August at the latest. However, New Brunswick's fixed election date is Sept. 27, so if the general election was called during the byelection then the Moncton North vote would be rolled into the provincial campaign.

There are 33 Liberals and 22 Progressive Conservatives in the 55-seat legislative assembly.

Under fire

In addition to his justice portfolio, Murphy also served as the government's house leader. He was moved to the justice portfolio in June after spending two years as health minister.

As health minister, he came under fire for his handling of the contract fight with the province's doctors and the controversial restructuring of the health system that slashed the number of regional health authorities to two from eight.

Murphy has five children: Timothy, 20, Tara, 18, Keegan, 17, Molly, 15, and Aodhan, 12.

This is the second high-profile cabinet minister that Premier Shawn Graham has lost in the last six months.

Former environment minister T.J. Burke stepped down on July 24, only a month after being moved from the justice portfolio. Burke said he was going to return to practising law, which he had to give up when he accepted a cabinet position in 2006.

Collins shuffled into cabinet

Murphy's exit from the cabinet has opened the door for Moncton East MLA Chris Collins, who has been promoted from the backbench to become the new minister of local government.

Murphy's cabinet responsibilities are being split up among three cabinet ministers.

Social Development Minister Kelly Lamrock is taking over as the province's attorney general. Meanwhile, Bernard LeBlanc is moving to justice and consumer affairs from local government.

Finance Minister Greg Byrne is assuming Murphy's duties as government house leader.