Visiting the home of the Vauxhall Astra, Gordon Brown said the 2,166 workers at the plant have fought through the recession and should be congratulated.
Brown told BBC news: "I’m very proud of what Ellesmere Port has succeeded in doing, despite the difficulties of the global recession of the last two years.
“They’ve come through, they’ve fought through."
The visit came as part of PM’s election campaign, and Brown has pinpointed plants like the Cheshire factory as key factors in recovering the economy.
Cheshire, and the site of the Vauxhall factory, is a key area in the forthcoming election, and the plant is at the centre of the local community.
The Ellesmere Port plant is recognised by owners General Motors as one of the most productive in Europe.
Home to the Vauxhall Astra, the plant could be chosen as the factory charged with making the new electric hybrid Ampera next year. The plant is capable of producing 50,000 Ampera cars per year.
The Ampera is an extended range hybrid car capable of zero emissions driving using an electric motor or with a petrol engine powering the motor.
Recently, the Ampera was driven 350 miles in a road test to the Geneva Motor Show.