DOES European Union negotiator Michel Barnier have a vested interest in boosting Theresa May’s credibility as a defender of UK national interests?

What other conclusion explains Barnier’s insistence on publishing his draft legal document on a “common regulatory area” between the Irish Republic and Northern Ireland that would consider the six counties as “part of the customs territory” of the EU?

Nothing could be more calculated to wind up the Democratic Unionist Party MPs on which May’s government depends for support.