I think this sums it up.
British politicians lied occasionally in the past; now lying was frequent and shameless. Nothing worked. The “bad eggs” used to resign; now they were promoted.
Because of our antiquated electoral system, our politicians have realised there are no consequences for doing bad things. Politicians with honour resign when something goes wrong. Politicians without honour tough it out. Thus we are left with politicians without honour.
And there's nothing we can do about it until five years are up.