Ottawa MP Paul Dewar is poised to join the race for the NDP leadership.
He urged followers on his Facebook page to join him for an important announcement on Sunday afternoon at the Lord Elgin Hotel in downtown Ottawa.
The 48-year-old was first elected to Parliament in 2006 and was re-elected in 2008 and 2011.
Dewar earlier organized a team of supporters across the country to measure support and financial backing for a leadership bid.
So far, only party president Brian Topp and Quebec MP Romeo Saganash have formally declared their intention to seek the leadership.
Other MPs are still weighing their chances, including Thomas Mulcair of Quebec, Peter Julian and Nathan Cullen of British Columbia, Pat Martin and Niki Ashton of Manitoba, Peggy Nash from Ontario and Nova Scotia’s Robert Chisholm.
Layton, the late NDP leader, died last month of cancer. He was 61.