Workers at Vauxhall's car factory have overwhelmingly supported a pay deal worth a lump sum of £750 and a 1.5% rise in January 2019.
The agreement mirrors one accepted by workers at the firm's van plant in Luton.
The Unite union said Vauxhall's owner, PSA, should repay the commitment of workers at Ellesmere Port with investment in new models at the facility.
Unite general secretary Len McCluskey said: "Unite's Vauxhall members at Ellesmere Port, like their colleagues at Luton's van plant, have overwhelmingly backed the pay deal.
"Our continued focus is to secure investment from PSA in new models at Ellesmere Port and guarantee the plant's long-term future.
"Time and again Ellesmere Port's top-class workforce has shown its commitment to the plant," he added.