Confidence vote
The real reason the permanent political class is trying to topple...
The reason Labour had a new leadership election process last time round, was the result of the parliamentary Labour Party and the NEC long term efforts to diminish the power of Trade Unions. By widening the vote to Labour voters, and quieting the voice of Trade Unions, the Blairite factions of the party gambled on those new voters being to the right of the Unions.