Ford and Jaguar announced last week they had reached an agreement with unions clearing one hurdle. The Transport and General Workers Union, representing workers in Jaguar factories in Birmingham and Coventry, agreed not to oppose building the X400 at Halewood.
Now the unions and Merseyside politicians are seeking government subsidies to refit the Halewood plant to nail down Jag- uar's commitment to the North-west plant. Other contenders are Germany and the US.
Tony Woodley, the TGWU chief negotiator, said: "We would expect the Government to act responsibly and remember that it is dealing with a British icon in Jaguar. The public would find it difficult to understand if they were seen to be letting the manufacturer take the car out of the country."
Eddie O'Hara, Labour MP for Knowsley South, said: "I think it is right that the Government supports Halewood and helps Jaguar meet the cost of refitting the plant to build the X400."
The Department of Trade agreed a grant of pounds 15m for the Halewood plant earlier this year when it was earmarked to build Ford's multi-activity vehicle.
But a Government source said Jaguar would need to make a fresh application for aid to help the X400 project. The company has not yet done so. A Jaguar spokesman said the X400 study team had not finished its feasibility study. The team was not expected to present its findings for "several weeks yet".