A former top official who served under Liam Fox has described Brexit as “swapping a three-course meal for a packet of crisps”.
Sir Martin Donnelly, who quit as permanent secretary of the Department for International Trade last March, said the UK risked losing its “economic advantage” by leaving the single market.
He also dismissed the government’s assertion that it can secure all the benefits of its current trading arrangements with the EU during Brexit negotiations as “something for a fairy godmother”.
Fox, the international trade secretary, is expected to give a speech on Tuesday warning against the UK joining a customs union, while Donnelly is set to give a talk in London on Wednesday that will undermine Fox’s Brexit plans.
In Fox’s address he will say the UK must be free to “exploit” trading opportunities outside the bloc and that joining a customs union with the EU will be “selling out” Britain.
Speaking on Radio 4’s Today programme on Tuesday morning, Donnelly said: “The challenge if we choose not to stay in the single market is can we negotiate equal access in all those areas of services without agreeing to the same rules as everybody else?
“And I am afraid I think that is not something for a negotiation, it’s something for a fairy godmother – it’s not going to happen.
“You’re giving up a three-course meal, which is the depth and intensity of our trade relationships across the European Union and partners now, for the promise of a packet of crisps in the future if we manage to do deals outside the European Union, which aren’t going to compensate for what we are giving up.
“You have to look at the arithmetic, it doesn’t add up I’m afraid.”