The group is planning a demonstration in London on Jan. 21 to oppose what it calls an attack on good jobs by Electro-Motive Canada.
The company locked out 420 workers on Jan. 1 after making a take-it-or-leave-it offer that the union says included a 55 per cent wage cut and other concessions.
Electro-Motive is owned by heavy equipment giant Caterpillar Inc. (NYSE:CAT) through its Progress Rail subsidiary.
Organizers say the demonstration will highlight Ottawa's failure to protect Canadian jobs.
OFL president Sid Ryan is also pushing for the province to step in by banning the use of scabs in labour disputes.
The federal Conservatives aren't commenting on the lockout at the plant, which Prime Minister Stephen Harper once used as a backdrop to tout business tax breaks.
Meanwhile, Ontario Premier Dalton McGuinty has said he is "very concerned" about the lockout and offered to provide mediation.
(CKOT, The Canadian Press)