Tory leadership candidate Jeremy Hunt has warned against taking a “very hard-line approach” in future Brexit talks.
The foreign secretary told the BBC this would provoke a “very hard-line response” from Brussels and would not resolve the current crisis.
He added that the UK had “made mistakes” in the negotiations with the EU so far.
The number of leadership candidates has risen to 12, with former Chief Whip Mark Harper declaring he will run.
Nominations for the contest to replace Theresa May as Conservative leader are due to open on 7 June, with the result expected in late July. The winner will also become prime minister.
Mrs May announced her resignation last week, amid widespread anger within the Conservative Party over her latest attempt to get her