A FAILURE to strike a good Brexit deal could lead to "horrendous" job losses at Oxford's BMW plant, union bosses fear.

Unite said thousands of workers' livelihoods rested on the Government's negotiations with Brussels and called for manufacturers to be protected.

Before the EU referendum it warned Mini production in Cowley could move abroad if Britain quit the bloc, with BMW saying it cannot speculate on its future in Oxford due to "political uncertainty".

The car-maker met with Oxford East MP Andrew Smith, who has now written to Prime Minister Theresa May and other top cabinet ministers to stress "how absolutely vital" the plant is to the city.

Mr Smith said executives want assurances they will not be hit by tariffs when shipping to Europe, "maximum freedom of movement" for workers and security for EU national staff, as well as deals that will keep common standards for components.

He said: "I have underlined how crucial BMW is to our community and to the UK economy and, along with other MPs, I will do everything I can to make sure the Cowley plant's future is secure."

His comments came as manufacturers group EEF, which includes BMW, warned Mrs May against "rushing through a clumsy Brexit" and urged her to maintain access to the single market.

But EU officials have insisted that will not be possible if the Prime Minister seeks curbs on immigration, something she is widely expected to do.

Norman Gough, branch conveyor for Unite which represents many of the Cowley workers, yesterday said he remained "confident" a solution would be found that allowed BMW to stay in Oxford but admitted: "The truth is no one knows".

He added: "All of us are concerned about the way things could go, but at the moment we can only speculate.

"It seems the only way we will get access to the single market is if we accept freedom of movement of labour, so that is going to be a key issue.

"Whatever the Government does it has got to get it right and I would certainly support protections for manufacturing.

"If things here were going to be scaled down, and at the moment I do not believe they will be, then the effect would be very bad. Going through those situations is always horrendous."

BMW says it is continuing with ‘business as usual’ for now, but senior figures at Oxford City Council said they were watching the situation closely.

Finance chiefs at the local authority have warned the company's departure would deal a "significant blow" to city coffers and have a wider "ripple effect" on the local economy.

It employs some 4,500 people at Cowley, including staff from more than 20 EU countries.

City council deputy leader Ed Turner said: "We are very concerned to keep them here, so the Government needs to give the automotive sector certainty as soon as it can.

"No one can be reassured from what we have heard to date and with regards to BMW, that is a situation everyone is watching very carefully."

A BMW spokesperson the firm could not "speculate" on its future plans until more was known about the future relationship of the UK and the rest of the EU.

He said: "BMW Group is committed to the UK, its fourth biggest market and home to two of its brands, and respects the British electorate’s decision to leave the EU.

"Given the current political uncertainty regarding next steps, all we can say regarding our own activities in Britain is that we continue to operate ‘business as usual’.

"Until we receive answers to the many open questions regarding the UK’s future trade relations with the EU and other countries, we cannot speculate about any possible impact Britain’s decision to leave the EU may eventually have on our UK operations."