The problem in the labour party is that there are a number of Blairite MPs who cannot accept that the party has democratically changed its underlying policy position and with that it's leadership.
I am one who does not feel that Jeremy Corbyn has led the party well regarding Brexit and the antisemitism issues. However, there are obviously many party members in the district and constituency parties that still have great belief in those present policies, and they prevail as the majority at this point in time and in that wish to retain Corbyn as leader to present those policies.
The parties present policies also have the support of the wider Labour movement along with the current leader. The trade unions are demonstrating some frustration with the Corbyn leadership on the two above issues. However, even if Corbyn were to be replaced as Labour party leader, the present policies would remain as there will be no going back to the Blair policies that so failed Labours grassroots members and working families throughout Britain.
Therefore, the remaining Blairite MPs and others with Blairite views in the party need to accept all the above and that things have very much changed
The constituency parties have the right under rule to select or deselect who it is that represents them in parliament. As long as that action is carried out democratically, then should the majority of a constituency party feel that their current MP does not represent their views or fully support current party polices then to deselect that MP is justified.
In short, those blairite MPs and others should cut out the whinging and whining and accusations of bullying etc and move on into the present Labour world. Blair and his policies are gone and they ain't coming back.