Boris Johnson has appointed a combative Eurosceptic as a senior adviser to his EU divorce team, the Telegraph can reveal, in a sign that supporters of a clean-break Brexit with infrastructure on the Irish border are now in the ascendancy on his leadership team.

Daniel Moylan, a former senior Johnson lieutenant during his days as London Mayor and Kensington and Chelsea councillor, has been an implacable opponent of both Theresa May’s Withdrawal Agreement and the Irish backstop.

The 63 year-old’s appointment was met with a mixed reception among moderates who have backed Mrs May’s deal, with one MP from that group observing that “we really are doomed” if Mr Moylan was in charge.

However, Brexiteers welcomed Mr Moylan as a breath of fresh air and a clear sign that Mr Johnson was serious about his promise to leave the EU on Oct 31 with or without a deal.

“We have seen in the past that if you try to accommodate both sides and sit on the fence you get splinters, so I very much welcome this stronger approach,” said one pro-Brexit Conservative MP.

Since the EU referendum, Mr Moylan has been a waspish presence on Twitter, frequently clashing with anyone who backed the May deal or the Irish backstop – until he deleted his account last week, apparently in preparation for the new role.