TORONTO - Ontario New Democratic Party chief Howard Hampton will trigger a leadership race Saturday by announcing that he will not seek re-election as leader at the party's next convention in March, 2009, The Canadian Press has learned.

Party sources said Hampton, 56, planned to announce his decision to step down as leader when he speaks to delegates at an NDP provincial council meeting in Toronto Saturday.

The sources told the news agency that Hampton would agree to stay on as the member of the legislature for Kenora-Rainy River, at least until the next Ontario election in 2011, but would step down as leader after 12 years.

He will tell the delegates that he wants to spend more time with his wife, Shelley Martel, and their two children, Jonathan and Sarah.

Hampton has been at the helm of Ontario's New Democrats since 1996, when he took over from former premier Bob Rae, who is now a federal Liberal MP.

There has been very few signs of candidates waiting in the wings for Hampton to depart so they could launch leadership bids, but a few names repeatedly come up including former elected New Democrats Marilyn Churley and Frances Lankin, who lost the party's last leadership race to Hampton in 1996.

Other names that are mentioned as possible leadership contenders include two of the party's newer members of the legislature, Cheri DiNovo and Peter Tabuns, both of whom represent Toronto ridings.

Hampton led the party through three provincial elections, but failed to make any real gains in popular support or the number of NDP seats in the Ontario legislature.

In fact, the party was hurt so badly by strategic voting in 1999 and 2003, which saw traditional NDP supporters voting Liberal in an all-out effort to unseat the unpopular Conservative government, that they failed to win enough seats for official party status.

Hampton had to ask the Conservatives to reduce the number of seats needed for official party status after the 1999 election so the NDP could ask questions in the legislature and tap into funds for caucus members.

But following the 2003 election, the NDP had to wait until March 2004 to again return to official party status when they took the Hamilton-East seat from the Liberals in a byelection.

The NDP struggled to have their voice heard in last year's Ontario election as voters and the media focused almost exclusively on Progressive Conservative Leader John Tory's unpopular plan to offer public funding for private religious schools.

Hampton's biggest election coverage last year came during a campaign stop in Hamilton when he lost his temper with the media for failing to look at what he said were the real issues affecting people's lives, repeatedly asking reporters why they didn't care.

The strain of the election campaign appeared to catch up with Hampton on voting day -- Oct. 10, 2007 -- as he choked up while talking about his father George, who died the previous year.

"This is a tough one. My dad has been involved in every election campaign since I was 14 years old, every one,'' Hampton said as he fought back tears walking into the Fort Frances, Ont., polling station with his mother Elsie.

"This will be the first election campaign in 41 years that he hasn't put up all the signs. That's tough.''

Hampton's wife, Shelley Martel, who had also served in Bob Rae's cabinet in the early 1990s, retired from elected politics before last year's Ontario election after 20 years as the member for the Sudbury riding of Nickel Belt, the same riding held by her father, Eli, for 20 years before her.

Hampton, the son of a mill worker, grew up in the northern Ontario community of Crozier and worked as a teacher and a labour lawyer before entering politics.

He was first elected to the legislature in 1987, and was both attorney general and natural resources minister in Rae's cabinet.

Hampton earned his law degree from the University of Ottawa, his Bachelor of education from the University of Toronto and his Bachelor of Arts from Dartmouth College in New Hampshire.