They have to appear to be, or else their vote is hopelessly divided between them and the Brexit Party, and then Labour would get in and the shit-storm which that would entail. Boris has no choice but to try to appeal to would-be BXP voters. Is he a hard Brexit man? No, he isn't. He pondered on whether to back Remain or Leave, remember? He is not Peter Bone, or John Redwood. He was never one of John Major's "bastards" like the others.
This is what he wrote in 2016, before deciding to back the Leave campaign:
"<The EU> is a market on our doorstep, ready for further exploitation by British firms,"
"The membership fee seems rather small for all that access.
"Why are we so determined to turn our back on it?"
And Remaining in the EU would be a "boon for the world and for Europe".
"I'm in favour of the single market. I want us to be able to trade freely with our European friends and partners."