Here... this is the post.
If JC fails to secure the support of the PLP after a Leadership contest, then there will be no effective opposition in parliament; he may not even be able to form a shadow cabinet.
He has already said that if he wins a leadership contest, he will "change the rules" and prevent MPs who have voted against him from standing in the next General Election - which might be as soon as October. Local Labour Party branches will be required to choose candidates who are supportive of JC but who may not be effective as candidates , won't secure the votes of the wider electorate, so the Labour majority in parliament may well reduce.