A single Walloon could sink British trade under Mrs May’s Brexit plan

SIR – If reports are to be believed, Theresa May is to agree with the EU a backstop for Northern Ireland that includes the entire UK staying in the EU’S customs union. This would apply until the EU is satisfied that a trade agreement “solves” the border issue.

Has Mrs May really understood what this would mean? Put simply, it means that even if 100 per cent of people in the UK wanted to leave the customs union, the UK could not do so without the EU’S agreement.

Worse, if the EU decides that any trade agreement with the UK is a so-called “mixed agreement” (as the deal with Canada was) it will require approval not only by the EU in the form of the Commission, the Council and the European Parliament, but also by parliaments in member states, including regional parliaments such as that of Wallonia.

One Wallonian parliamentarian could prevent the will of the entire UK population from being carried out. Tim Hammond

London SW6 SIR – I can only assume that No 10 is working on an agenda to keep the UK in the EU, against the will of the majority in the 2016 referendum.

Conservative MPS from all wings of the party support a Canada plus plus plus deal, and even the EU is keen to conclude a free-trade deal of this sort.

Yet the Chancellor claimed on the Today programme this week that the EU had never offered such a freetrade deal and the Prime Minister continues to push the deeply flawed Chequers plan that prevents UK business from freeing itself of present and future EU regulation, prevents the UK from benefiting from freetrade deals with the other 160 or so countries of the world and prevents the UK from setting tariffs that reflect the country’s needs.

This is the sort of arrogant behaviour by an out-of-touch leadership that has historically prompted revolution. Alastair Macmillan

Director, White House Products Port Glasgow, Renfrewshire SIR – The EU is terrified of the UK leaving the customs union and being free to manage its own trade for the benefit of UK citizens. EU citizens will then wonder why, to participate in a trade deal, they must pay billions to an unelected, unaudited bureaucracy. John Westwood

East Grinstead, West Sussex

SIR – Theresa May should realise that any deal that leaves the UK in the customs union will hand power to Jeremy Corbyn.

The reason is simple. The millions of Ukip voters who voted Conservative at the last election will return to Ukip in protest at the next election. The split vote will let Mr Corbyn romp home. Mrs May will reap what she has sown. Guy Aston

Doncaster, South Yorkshire

SIR – If it stops supporting the Government, will the DUP be giving us our money back? Brian Earle

Hawkhurst, Kent