Jennyluck
As leader of the house during brexit, his job was to be impartial. He absolutely wasn’t.
Labour are welcome to him.
He wasn't leader of the house; that's a different job altogether.
The HOC's speaker's job is to defend the primacy of the House of Commons from government encroachment.
Under our constitution there are three arms of government, the Legislature, which scrutinises and passes laws, the Executive which makes policy and proposes laws and the judiciary which interprets those laws when cases based on them are brought to court.
The Executive represents the Crown in parliament but its power is restricted by the fact that Parliament, which is the Legislature, is supreme. Parliament (i.e all MPS, regardless of party) is able to use its vote to dismiss any legislation the Executive proposes. The Executive cannot prevent it from doing that.
Naturally the Executive tries all it can to get its own way and, when it has a big majority, as does the current government, its proposed legislation is unlikely to be voted down. It is the job of the Speaker to frustrate the Executives 'tricks' and ensure that what passes is the will of Parliament, which is not necessarily that of the government. If they appear to be 'favouring' the opposition it is because the government is trying to exceed its powers. Nothing whatsoever to do with lack of impartiality...
During the latter part of Bercow's stint as Speaker he was dealing with an Executive that had a very slight majority but was trying its hardest to bypass parliamentary scrutiny. Of course he thwarted it from time to time. That was his job...
We fought a nasty Civil War in the 17th C to bring about this constitutional arrangement. It's very sad that people don't understand constitutional principles ...