Leaders of about half of Britain's largest companies have made a last ditch appeal to their employees to vote for remaining in the European Union.

In a letter to the Times on the eve of Thursday's vote, some 1,285 business leaders — include representatives of half of the FTSE 100 businesses — argue that a vote to leave will hurt the British economy.

Similar letters have been released in the course of the acrimonious campaign. But Wednesday's letter is clearly meant to make the 1.75 million people employed by the signatories to think twice about their vote.

"Britain leaving the EU would mean uncertainty for our firms, less trade with Europe and fewer jobs," the letter says.

The companies represented include Barclays, Standard Life and Anglo American.