Toyota has issued a warning against the proposed withdrawal of Britain from the European Union, claiming that Brexit could lead to duties of as much as 10 per cent on its UK-built cars.

In a letter to its British employees, Toyota said that a Brexit would force it to either cut costs or to make its cars more expensive to compensate, and thereby risk hurting sales.

According to Toyota’s sales statistics, almost 90 per cent of the vehicles that it builds in its several UK plants are exported with three quarters of those going on to be sold in the European Union.

90% of UK-built Toyotas exported

The letter said: “Continued British membership of the EU is best for our operations and our long term competitiveness. We will face significant business challenges as a result of a decision to withdraw from the EU.”

Having invested more than $59 billion in the UK, Toyota built nearly 200,000 Avensis and Auris models in its Burnaston plant last year and more than 235,000 engines and components in Deeside.

As a result, it has been vocal in its support of Britain remaining in the EU ahead of Thursday’s referendum and has been joined by fellow Japanese manufacturers Nissan and Hitachi.

"Widespread concern"

The Society of Motor Manufacturers and Traders (SMMT) said in a statement that carmakers are sharing “widespread concern” related to Brexit, with the possibility of it jeopardising jobs and investment.

Earlier this year, the BMW Group sent a similar letter to its UK-based employees warning them against voting leave, stating that Brexit would lead to “higher costs and higher prices”.

Likewise, in March Honda expressed a show of faith in the British car building industry by pouring an additional £200 million into its Swindon plant, as part of its “long-term commitment” to the UK.

To read more on how Brexit could affect the UK’s car industry, click here.