Seems to be desperate to get himself sacked at the moment.
Some politicos I follow seemed to think that his latest strategy is to get sacked, and therefore sit out the Brexit shitstorm from the back benches, then ride in as a saviour when everyone elses reputation has been ruined.
Resigning wouldn't work as that would appear that he's shitting out of it.
I wouldn't put it past him at all, literally thinks of his own career ahead of anything else