BMW will shut down its Oxford plant in the four weeks after the UK leaves the EU.

Uncertainty over the country's future after Brexit has forced the car manufacturer to take the unprecedented step to move its annual summer maintenance period from August to April next year.

Workers at the plant, which employs 4,500 people, were told of the change yesterday with many - particularly those with children - speaking out about the significant disruption it will cause.

The city's leaders have rallied behind the plant's move saying it shows the government must provide assurances to businesses about customs and tariffs on the UK's borders after Brexit.

MP Layla Moran called on the Prime Minister Theresa May to come to Oxford to reassure affected workers and explain her Brexit strategy.

She said: "This is not a rash action but a cool-headed business decision.

"It shows the real impact a 'no deal' scenario is having on jobs and the economy in Oxford - the Government's actions are now directly putting the jobs of the people I represent at risk.

"It is devastating for the people involved and I demand better for my constituents."

Under the plans revealed yesterday, the Cowley plant will close for four weeks from April 1 - two days after the UK's planned EU exit date of March 29.

Maintenance work and preparing the plant to manufacturer the new electric Mini will now take place during this period as opposed to during the summer.

Staff will be encouraged to take annual leave or can build up overtime to cover the shutdown with those choosing not to do this going unpaid for the entire period.

The shutdown usually coincides with the summer holidays and plant workers now may have to take an extra holiday in August to look after children.

Plant bosses stressed staff are not usually told when maintenance periods for the following year will be held until November and they are trying to give people as much notice as possible to give them time to plan.

A spokesman said: "Planned annual maintenance periods at BMW Group production sites allow essential updating and equipment replacement to be completed over several weeks, while there is no production taking place.

"As a responsible organisation, we have scheduled next year’s annual maintenance period at MINI Plant Oxford to start on April 1, when the UK exits the EU, to minimise the risk of any possible short-term parts-supply disruption in the event of a no-deal Brexit.

"While we believe this worst case scenario is an unlikely outcome, we have to plan for it.

"We remain committed to our operations in Britain, which is the only country in the world where we manufacture for all three of our automotive brands."

Earlier this year BMW called for certainty about whether car parts will be stopped on the borders post-Brexit, warning any delay will damage its business.

Hundreds of lorries arrive at the plant every day, bringing parts from across the world, with 60 per cent of these coming from the EU.

Car manufacturers have made a series of interventions recently in an attempt to get clarity for the future with Honda warning on Tuesday that a 'no deal Brexit' could cost it 'tens of millions' and Jaguar moving staff to a three day week.

Now the decision to move the shutdown has been made it will not be changed again regardless of what happens in the next months of negotiations, according to the plant.

The many locally-based suppliers who work with BMW were being told of the plans yesterday with the knock-on effect in the area's economy likely to be massive.

Oxford East MP Anneliese Dodds, who's constituency includes the plant, said she hoped BMW's actions would be a 'wake up call' for those in Government to 'end the ambiguity' over Brexit.

She added: "I feel like I have been banging my head against a brick wall on the issue of customs arrangements after Brexit and have raised the issue with the Prime Minister.

"BMW need to know what our exit strategy is going to be and they have been given nothing by the Government.

"Those in charge of this need to realise talking about a 'no deal' is having a real world impact.

"I hope they can see this is not a case of businesses scare mongering - they are trying to plan for the future in a situation of great uncertainty."

As the news broke from the plant yesterday, workers and their relatives took to Facebook to discuss the decision.

One woman said her husband would miss their child's first summer while another said it would 'ruin the holidays for the kids.'

The union Unite, which represents many of the workers at the plant, said the shutdown was a 'sensible precaution'.

Assistant general secretary Tony Burke said: “BMW’s decision underlines the uncertainty facing one of the UK’s flagship industries. Unite is working with businesses like BMW to mitigate the worst effects of the Tories’ Brexit chaos, but working people are losing out as the uncertainty bites and carmakers stall on investment plans."