Previously one of the most loyal Tory MPs. Except on Brexit. Will be one of many key tests of where the mood of the country is now, if he can hold on to his seat in the now almost inevitable election.
The next election is bound to be a bloodbath one way or another. I shouldn't be surprised to see Philip Lee lose his seat, for sure. But to call someone who, until today, had been a member of the Conservative Party for 29 years, an MP for 9 of them, and who had basically never voted against the government in that time a "treacherous rat" speaks volumes about the state of politics now.
Personal opinion: If a elected MP leaves their party mid term, it should automatically mean a bi-election in that constituency. Too many people vote for the party rather than the candidate. His election victory is therefore bogus.