Pursuing a “hard” Brexit could alienate core Conservative voters and cost the party the next general election, a group of Tory MPs has warned.
The group – which includes ex-attorney general Dominic Grieve – said “a moderate core” of Tory voters do not want the party to become “UKIP-lite”.
PM Theresa May must ensure she is not “pushed” into a hard Brexit, they said.
It comes as the Lib Dems overturned a 23,015 Conservative majority to win Thursday’s Richmond Park by-election.
Ex-Tory MP Zac Goldsmith stood as an independent after leaving the Conservative Party, but Lib Dem Sarah Olney – who fought the campaign on the issue of Brexit – won by more than 1,800 votes.
Writing in the Observer newspaper, Mr Grieve, former Foreign Office minister Alistair Burt, ex-transport minister Claire Perry, education select committee chairman Neil Carmichael, and Bath MP Ben Howlett, said the Richmond Park result must serve as a wake-up call for the party.
“The Conservative Party needs to be alert that there is a moderate core of Conservative voters, who voted Remain, and who want to hear the Conservative government speaking above the noise of the Brexiters,” the quintet wrote.
“They do not want the Conservative party to be UKIP-lite, nor to hear that their desire for a negotiated Brexit, with all options open for the prime minister, is an attempt to delay the process or simply an expression of Remoaning.”
The Richmond Park result should be a reminder “that their votes have another destination if we don’t get this right,” they added.
They called for Downing Street to reveal its negotiating position on Brexit before triggering the formal exit process under Article 50 of the Lisbon Treaty.
Such a move would ensure the government was not “pushed into a corner by those who only advocate a hard Brexit,” the MPs added.