Brexit: Liam Fox says future trade situation 'more complicated' than 'packet of crisps' analogy levelled by ex-Government adviser

International Trade Secretary used keynote speech to warn that staying in European customs union would be a 'complete sell-out' of Britain's interests

Liam Fox has declared that “Brexit is more complicated than a packet of Walkers”, after an ex-Government adviser claimed leaving the bloc was like swapping a “three-course meal” for the promise of a “packet of crisps”.

The International Trade Secretary hit back at Sir Martin Donnelly’s mockery of plans to leave the European customs union and strike free trade deals further afield, using a keynote speech to warn that any form of customs unions with the EU after Brexit would be a ”complete sell-out” of Britain’s interests.

Outlining his vision for future trade after Brexit, Dr Fox said there were real opportunities for Britain to show leadership on the global stage, but only if struck out on its own rather than “ceding control” to Brussels.

It comes as Theresa May faced growing pressure over customs union membership, after Jeremy Corbyn unveiled a dramatic shift in Labour’s Brexit stance in favour of a “new and comprehensive” customs agreement to allow tariff-free trade with the EU.

Pro-EU Tory rebels are threatening to join forces with Labour to keep membership on the table in a potentially devastating Commons revolt for the Government.

Asked about Sir Martin’s comments during a speech in London, Dr Fox said: “It’s unsurprising that those who have spent a lifetime working within the European Union would see moving away from the European Union as a threat.”

The prominent Brexiteer went on: “We are already trying to seek a full and liberal partnership with with the European Union; we are already having discussions about expanding our trade agreements beyond the EU, and we are also taking about rolling over the EU agreements into UK law, so that we get no disruption in terms of market access on exit.

“So its not a choice of one or the other, and in any case, I think the UK Brexit process is, as we have all discovered, a little more complex than a packet of Walkers.”

Sir Martin, who was permanent secretary at the Department of International Trade (DIT) until last year, told BBC Radio 4’s Today programme that striking new free trade deals with countries like the US would not compensate for the loss of access to the EU trade agreements.

He said it was like ”giving up a three-course meal for the promise of a packet of crisps” later, and the UK would need a “fairy godmother” to get the EU deal it is seeking.

Asked about the matter, Dr Fox said: “Neither Sir Martin, with all due respect, nor anyone else has seen the full details of what was agreed at Cabinet last week at Chequers.

“And the Prime Minister sets those out on Friday; I think people will find that what we need is a hard-headed leader, not a fairy godmother.”

The row came as Dr Fox became the latest in a series of senior cabinet ministers to make a “Road to Brexit” speech, which will culminate in an key address by the Prime Minister on Friday, where she is expected to set out plans for Britain’s future relationship with the EU as agreed by her Brexit war cabinet last week.

Ms May is scrambling to finalise the details by Friday, as Brexiteers also threaten her leadership from the right if she fails to seek an agreement that allows the UK to agree trade deals – something staying in the customs union would preclude.

She also faces pressure from Labour after Mr Corbyn ended months of speculation by finally committing his party to remaining in a customs union.

Speaking at Bloomberg in London, Dr Fox branded Labour’s policy shift as an “incoherent, inept and clueless performance”, which he claimed would be “funny if it wasn’t so tragic”.

He also raised the prospect of a TTIP-style deal of privatisation if Britain stays in the customs union, something that Labour opposes.

Dr Fox said: ”Remaining in a customs union of any type would only make sense if we were to abandon our global ambitions and limit our abilities to shape our trade policy, and the changes to the global environment that I have outlined.

“Tomorrow’s choices would be constrained by today’s status quo.”

His speech drew mockery from his Labour counterpart Barry Gardiner, who said the Tory minister was ”divorced from reality and isolated from British businesses and workers”.

But Allie Renison, of the Institute of Directors, said: “We believe that the Government can square the circle between pursuing its own independent trade deals with third countries and ensuring businesses in the UK face minimal barriers to trading with the EU.

“Keeping tariffs on industrial goods aligned with the EU would still allow plenty of negotiating capital for future trade deals, including with the US, while ensuring companies avoid costly rules of origin that could jeopardise foreign investment into UK manufacturing and disrupt the UK’s integration within European supply chains.”

The Prime Minister’s plan is set to be approved by full Cabinet at a special meeting on Thursday.

The proposal – which was immediately described as ”pure illusion” by European Council president Donald Tusk – is understood to involve a promise to keep UK standards as high as European ones, as well as the creation of a dispute mechanism for cases where Britain wants to go its own way.