The British government helped to secure a more than £240 million ($310 million) investment from Toyota in its English plant with a letter reassuring the carmaker about post-Brexit trading arrangements, two sources said.

Toyota said on March 16 it would install its new car platform at its Burnaston plant. One source, who is familiar with the letter, said that Toyota delayed the decision, which was due by the end of December, to weigh a number of factors including the upcoming British exit from the European Union.

The business ministry has confirmed the existence of a letter but refused to release it.