The Vote Leave campaign bus. Steve Baker told colleagues there was a way “to spend as much money as is necessary to win” the referendum

A Brexit minister has been caught up in the controversy surrounding spending by the campaign to leave the European Union because of a memo he wrote in early 2016.

Steve Baker, a leading figure in Vote Leave and now a minister in the Department for Exiting the EU, told colleagues that his organisation had found a way “to spend as much money as is necessary to win”. The law states that only the designated main referendum campaigns could spend £7 million before the vote. Other organisations that wanted to take part would have had to register with the electoral commission and could have spent up to £700,000, providing they proved there was no controlling influence from the designated campaign.

However Mr Baker’s email said: “It