Liam Fox has warned a “worst of both worlds” soft-Brexit customs union would result in the UK market being treated as commodity by the EU in its own trade arrangements.

In a letter to the chairman of the backbench 1922 Committee Sir Graham Brady seen by The Telegraph, the international trade secretary also lays out that agreeing to a post-Brexit customs union with Brussels would mean the UK would have to apply the bloc’s Common Customs Tariff (CCT) on third-country goods and would “stymie the UK’s ability to open markets around the world.”

The warnings come as the Government continues negotiations with the Opposition to gain support for Prime Minister Theresa May’s controversial Withdrawal Agreement, with Labour pushing for a customs union with the EU.

Dr Fox points out that a post-Brexit customs union agreement with the EU would be “not a meeting of equals” but where the UK market would be treated like a commodity by the EU and “We would ourselves be traded. As the famous saying in Brussels goes, if you are not at the table, you are on the menu.”

The international trade secretary went on to explain that this state of vassalage would “allow the European Union to negotiate access to UK markets as part of EU trade policy… i.e., it will be able to grant access to the world’s fifth largest market as part of any EU offer, without the need to balance this access by negotiating on key UK offensive interests.”

“This is because the UK as a non-EU member state would have no say under EU treaty law for the formation and agreement of EU trade policy.

“We would be stuck in the worst of both worlds, not only unable to set our own international trade policy, but subject, without representation, to the policy of an entity over which MPs would have no democratic control,” he stated.

Tories Face Election Backlash if They Fail to Deliver Brexit https://t.co/NDy5I7Fo8D — Breitbart London (@BreitbartLondon) April 9, 2019

Countering assertions that the UK would still be able to pursue ambitious free trade agreements with third countries, such as the United States, the Brexiteer Tory minister said “it is worth noting not only that we would have to apply the CCT with third countries, but that countries who [sic] negotiate free trade agreements (FTAs) with the EU would have automatic access to the UK market without the UK having… reciprocal access unless a new agreement was bilaterally negotiated.”

“The key question is that if a trading partner already had access to the UK at no cost, why would it be interested in negotiating a further bilateral agreement?” Dr Fox asked.

The letter was revealed as Brexit Party leader Nigel Farage warned against the prime minister’s Withdrawal Agreement with “Corbyn’s soft Brexit bolt-ons.”

He told his followers on social media Monday night that what Mrs May “wants to sign up to with Mr Corbyn is membership of the Customs Union which means we can’t set our own tariffs, we can’t do our own trade deals, all things that we were promised, that if we voted to leave in the referendum we would get, all things that were promised in her own manifesto.

“Not only is this the most incompetent and worst prime minister in my lifetime, but she’s also the most duplicitous and dishonest, as well,” Mr Farage added.