Prime Minister Stephen Harper has called a byelection for March 19 in the Toronto-Danforth riding of the late NDP leader Jack Layton.

The prime minister's office announced on Sunday that March 12 was to be the date for the byelection, but it issued a revised press release Monday to change the date.

The new date means the byelection will be held in the same week as the NDP holds its convention in Toronto to select a new party leader, who will succeed interim leader Nycole Turmel. That leadership vote is March 24.

The eight candidates vying for the position are Niki Ashton, Nathan Cullen, Paul Dewar,Thomas Mulcair, Peggy Nash, Romeo Saganash, Martin Singh and Brian Topp.

NDP members living in the Toronto riding east of the downtown core chose law professor Craig Scott to replace Layton as the party's candidate three weeks ago.

Also on Sunday, the Conservative Party announced communications consultant Andrew Keyes as its candidate in the riding.

Adriana Mugnatto-Hamu was selected as the Green Party candidate at a nomination meeting on Sunday afternoon.

The Liberal Party has not held its nomination meeting yet.

The next NDP leadership debate will be in French on Feb. 12 in Quebec City, followed by another three debates in Montreal, Winnipeg and Vancouver.

Layton, who led Canada's Official Opposition, died of cancer last August. He was 61. Layton led the NDP to a historic win in the last federal election, garnering 103 seats and landing the party official Opposition status for the first time.

A former Toronto city councillor, Layton held the Toronto-Danforth riding for more than seven years prior to his death.

The riding represents a diverse section of the city. Affluent neighbourhoods sit next to co-operatives and social housing. The area also includes large Chinese, Greek and South Asian communities, whose support will be key for the NDP to hang on to the seat.