Tony Blair (yeah, I know):

Theresa May’s Brexit plan is ‘literally not going to happen’ says former prime minister Tony Blair

Furthermore:

Blow for Theresa May as EU parliament rejects climbdown offer on post-Brexit migrants

The Brexiteers are very much like Trumpers (which is why some Brexit champions also were Trump champions) - they want a pretend world where there is no cost for things like xenophobia.