Japan's government has warned that Brexit could result in the country's firms moving their European head offices out of Britain, BBC News reports.

The strongly worded report from Japan's foreign ministry says the firms might want to move "if EU laws cease to be applicable in the UK".

It calls on Theresa May's government to deal with the companies' concerns in a "responsible manner".

Downing Street received the report earlier this week, the BBC understands.

Japanese firms employ an estimated 140,000 workers in the UK, with Nomura bank, manufacturing giant Hitachi and carmakers Honda, Nissan and Toyota all having major bases in the country.

The letter warns: "Japanese businesses with their European headquarters in the UK may decide to transfer their head-office function to Continental Europe if EU laws cease to be applicable in the UK after its withdrawal."