WARNINGS from the Oxford's largest employers and the city's first Brexit casualty could lead to a business exodus unless the Government provides certainty over customs arrangements, MPs have warned.

The exhortation comes after BMW customs manager Stephan Freismuth hinted the Cowley MINI plant could close if car parts were caught up in post-Brexit delays.

Airbus, whose helicopter division is headquartered in Kidlington, has threatened the leave the UK in the event of a 'no-deal' Brexit and Unipart warned 'busloads of jobs' could disappear into Europe.

As uncertainty grew this week, Oxford lost its first business to Brexit as Heathrow Airport operator Ferrovial announced plans to move from Oxford to the Netherlands in order to remain within EU regulations.

Oxford East MP Anneliese Dodds warned that unless the Government started listening to businesses more would follow.

She told the Oxford Times: "I am deeply concerned by the news about Ferrovial, which follows strong warnings from Unipart and BMW – all of these firms are very important local employers.

"They are not voicing their concerns about Brexit to make a political point, but because continuing uncertainty about customs and other arrangements after Brexit poses huge problems for their business models."

She added: "I really hope that government now starts listening to business about the damage that will be caused by an abrupt and chaotic Brexit- before more firms follow Ferrovial's example and vote with their feet."

Oxfordshire Local Enterprise Partnership chief executive Nigel Tipple attempted to reassure businesses and said new economic opportunities, especially in the 'Oxford to Cambridge corridor' plans, were around the corner.

He said: "As we approach the UK’s withdrawal from the European Union, our message to the Oxfordshire business community continues to be one of reassurance.

"Of course businesses are concerned as to what Brexit terms will be negotiated in the coming weeks and months, but our county’s economy remains one of the most agile in the UK."

Oxford City Council leader Susan Brown, who is also chairman Oxfordshire Growth Board, said she was 'really concerned' by BMW's warnings and appealed to the Government for clarity.

She said: "We are very reliant on EU workers in Oxford and it's important that the Government also send a clear message to reassure them they are welcome here."

She stressed that the city was an attractive place for businesses and 'hugely important' for the UK's economy.

Following the comments by Mr Freismuth, the firm's special representative to the UK Ian Robertson told The Oxford Times that the Cowley plant was not under threat.

He said: "Our priority is to avoid unnecessary costs to our business but that is not a threat to the Oxford plant.

"Delays at customs and increased paperwork are things we would look to avoid: we are not prepared to see an increase in the price of a vehicle and we don’t think our customers are either."

Mr Robertson said production of the electric mini would go ahead as planned at Cowley in 2019.

Heathrow Airport operator Ferrovial revealed this week it would be moving its international holdings company from Oxford Science Park to Amsterdam to remain under EU legislation.

The announcement comes just days before the science park opens its new £13m Schroedinger Building as part of a major expansion.

But the park's managing director Piers Scrimshaw-Wright said that despite Ferrovial's exit, demand was high.

He said: "We are seeing record demand for space.

"We already have two occupiers for our new Schroedinger Building (Fuel 3D and Oxford Sciences Innovation), with more expected to be announced soon.

"The Oxford life science and technology sectors in particular are continuing to see huge investment, both domestic and international."

More local jobs were put at risk last week when Airbus, which employs hundreds of people at the base of its helicopter division in Kidlington, published a risk assessment online.

The firm said it would 'reconsider its investments in the UK and its long-term footprint in the country' if Britain crashed out of the single market and customs union.

Oxford West and Abingdon MP Layla Moran wrote in a blog post on Huffpost yesterday: "This wasn’t a threat. This was the first stage of its disinvestment from the UK; the risk of a no-deal Brexit is now simply too great, and too soon."

She added: "It will only take a handful of high-tech engineering companies of the size and prestige of Airbus to make such a pronouncement and you could quickly see how the quiet march could degenerate into a stampede to get out of Brexit Britain."