Speaking at an Institute of Government event yesterday, Mr Fox said ongoing uncertainty over Britain’s membership of the customs union was hampering his efforts to strike deals with non-EU countries after Brexit. He also warned he would quit his post in the event that Mrs May signs Britain up to a permanent customs union, as advocated by Labour leader Jeremy Corbyn. Stressing the need for a deal over future EU customs to be “done and dusted” by the next general election, currently fixed for 2022, he added: “There would be a major disincentive for other countries to want to negotiate with us in a period where they didn’t know when the end of our customs union with the European Union would be, and it’s likely therefore, we would delay those discussions.
“That’s not something I want to see.”
Speaking subsequently on BBC Radio 4’s Today programme, Mr Fox said he did not believe MPs would accept the Government entering into a permanent customs union with the EU after Brexit in any case.
He added: “I don’t think Parliament would actually accept the concept of a permanent customs union for a whole range of reasons that I’ve set out – and I don’t think it would be acceptable inside the Conservative Party.
“Of course we do have a temporary customs union inside the implementation period, that is already accepted, but one of the reasons that we embarked on this particular process was so that we would be out of these arrangements by the time we got to the next general election.”
Dr Fox said the Government would do “everything possible” to avoid a no deal border between Northern Ireland and Ireland and “uphold the Good Friday Agreement”.
He said: “In a no-deal scenario, the UK Government is committed to entering into discussions urgently with both the European Commission and the Irish governments to agree a long term.”
Asked whether Theresa May should set a departure date, he said: “I don’t know because I can’t speak for the individual MPs involved and whether they think that is a determining step in the process, but we certainly need to get the argument across to the whole of the House of Commons that at the referendum almost three years ago they were given an instruction by voters – why have they not carried it out?”
Speaking in October, Victoria Hewson, senior counsel with the International Trade and Competition Unit at the London-based think tank the Institute of Economic Affairs, told Express.co.uk Mr Fox’s job was becoming “increasingly difficult” as the process of Brexit dragged on.
She explained: “What he is possibly trying to do is get out there and make the case and show the opportunities there are when and if the UK is free to do trade deals.
“However, it’s hard to know how long they will have to wait.
“These things take time but if we had a end date and knew when this would be coming to a conclusion, I think most countries would probably bear with that.
“I think in this case it is certainly about how long it takes to get there.
“The uncertainty is a drag on morale.”
Meanwhile a Westminster source suggested even Brexit-backers such as Mr Fox had come under increasing pressure from the eurosceptic European Reform Group (ERG) for perceived compromises over the course of the last six months.
He added: “He is undoubtedly in a very difficult position.”
Their comments came in the week Mr Fox himself voiced his support for Mrs May.
Speaking in New York, he insisted she would be the UK Prime Minister who “leads us out of the European Union at the end of March 2019”.