More than 420 auto workers in southwestern Ontario have been locked out of their jobs after contract talks with their employer hit an impasse.

Electro-Motive kicked off the new year with a work stoppage against CAW members at its London, Ont. plant, the site of a bitter labour dispute over wages and benefits.

The move comes about a week after the company presented workers with a final offer that would slice union wages in half, eliminate pensions and nix other benefits.

"We're dealing with a bully of a company here," Employee Frank Vanwiechen said from a late-night picket line.

"When I deal with a bully I say ‘get reasonable, calm down.' We tried that method, it's not working. We're onto the next stage."

Vanwiechen is referring to heavy equipment goliath Caterpillar, which owns Electro-Motive through its Progress Rail Subsidiary.

The company has a history of butting heads with unions, including a highly publicized dust-up with the United Auto Workers in the 1990s.

"Caterpillar may be one of the richest corporations to ask for the deepest of cuts," CAW President Ken Lewenza said in a statement.

He went on to call the lockout an attack on working people, their families and the overall London area.

The affected CAW members set up pickets outside Electro-Motive's London plant on Sunday evening, the same day their previous contract expired.

"Our goal is not to have incidents on the picket line, it's just to try to get back to work and give these workers an opportunity to earn a living for themselves," said union representative Fergo Berto.

Speculation about the future of Electro-Motive's London plant intensified in October when Progress Rail opened a plant in Indiana. Questions were raised about whether the company wanted to relocate to avail of "Buy America" legislation across the border.

Back in London, picketing CAW workers remain anxious about their futures.

"This affects my wife, this affects my children, (it) affects the businesses I patronize," said Vanwiechen.

Meanwhile, Ontario Federation of Labour president Sid Ryan said supporters are ready to help the CAW prevent scabs from crossing picket lines.

"Workers across the province are angry and feel betrayed by their government and they are ready to fight together to defend good jobs," he told The Canadian Press.

Officials told CTV SWO that Electro-Motive does not have plans to use replacement workers at the moment.

With files from CTV Southwestern Ontario and The Canadian Press