[joeysteele]

Originally Posted by arista

Sure.

But a By Election must now be called

Not really.
He will be an independent MP when he returns if the Cons don't allow him back.

An MP cannot be sacked, they need to resign their seat.
He's not doing that.
His constituency can do a recall motion but that has to reach a required level of numbers.

So umless he resigns as an MP or he had a serious criminal conviction then he can remain an MP until the next election.
A by election cannot be called if the sitting MP is still an MP and will not resign as one.