Earle McCurdy made the announced during a news conference today at a hotel in St. John's.
Lorraine Michael announced last week that she would step down as party leader after a leadership convention.
The party's executive is scheduled to meet later today to decide where and when the convention will be held.
McCurdy retired in November after serving for two decades as president of the Fish Food and Allied Workers Union.
New Democrat MP Ryan Cleary, who was among McCurdy's crowd of supporters, says he will not seek the leadership. (VOCM)