Splits within the Conservative Party will emerge if the leadership contest is solely influenced by the EU referendum, Stephen Crabb has claimed.
The leadership hopeful called for an end to the labels of "Remain" and "Leave" to describe his colleagues to avoid deep divisions.
Work and Pensions Secretary Mr Crabb, who backed Remain, faces an uphill task to be among the two candidates put before Tory members with Brexit backers Andrea Leadsom, Michael Gove and Liam Fox also in contention.
Frontrunner Home Secretary Theresa May supported Remain.
Mr Crabb, appearing on ITV's Peston On Sunday, said: "I think the quicker we get past using these labels the better and every day that goes by that we as colleagues use labels like 'Remain' or 'Leave' to describe each other, the deeper the division that will be in the party.
"I tell you, if we allow this leadership contest to be seen just through the prism of whether you are 'Leave' or 'Remain' we risk splitting the party - mark my words."
Mr Crabb added: "We're all committed to taking Britain out of the European Union. We all stood on a manifesto, all Conservative MPs, to hold a referendum and abide by the outcome of that referendum so we all share a commitment to taking Britain out of the EU.
"That's what builds trust and I think what really builds trust with members and the country at large is showing now we've got a clear idea about how we're going to do it and what our principles will be that will guide a negotiated exit."
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