A group of Tories have vowed to be the resistance to what it dubbed the “harsh Brexit” now apparently planned by Theresa May.

The Conservative Group for Europe set out its stall ahead of the Brexit talks, pledging to fight the economic damage it fears from severing links with the Single Market.

An 80-strong reception at the Birmingham conference heard an impassioned call to fight back from senior Conservative MP Neil Carmichael – who joked that the referendum result had driven him to drink.

There were loud cheers when Mr Carmichael, the chairman of the education select committee, said that 55% of voters in his Stroud constituency had voted to Remain.

Mr Carmichael said: “We would be reckless if we did not challenge some of the consequences of a hard, or harsh, Brexit.

“Because we have got to understand that, if it is a hard Brexit, it is also a harsh Brexit.

“We must avoid, at all costs, a Brexit that damages our economy, damages our capacity as a nation to perform capably in the future and actually damages Europe.”

Mr Carmichael – speaking after the Prime Minister signalled that immigration controls would trump Single Market access in her Brexit talks – said “proper connections” with the EU’s trading arrangements were essential.

He told the group, which he chairs: “We have got to find a way of making sure that actually happens

Criticising “total abandonment and total recklessness”, Mr Carmichael added: “The Conservative Group for Europe has a job to do. The key thing to have in our minds is that our national interest matters.”

The Stroud MP described how he had gone through a type of “bereavement” since the referendum result, but joked: “I’m getting thru it.

“I’ve put on a bit of weight, probably a bit of extra drinking when I shouldn’t have been doing that – those late night occasions when you think ‘Wow, this is really happening!’

“And you have a bit to drink and you think, ‘No it’s not,” – then you wake up in the morning and you discover “Actually it is”.

Mr Carmichael also poked fun at Ms May’s Great Repeal Act, pointing out its name resembled the 1832 Great Reform Act, which “didn’t do us a huge amount of good”.