The Independent Group can no longer be dismissed as a home for disgruntled anti-Corbynite Labour MPs, as three Tories have joined them: Heidi Allen, Anna Soubry and Sarah Wollaston.

Brexit has driven them out, they confirmed in a joint statement, blaming Theresa May's "dismal failure to stand up to the hard-line ERG" and accusing the party of being "in the grip" of Jacob Rees-Mogg's group. Mr Rees-Mogg could only wish he and his fellow Tory Brexiteers had such control over the Prime Minister given the way she has handled Brexit.

Ironically, Ms Allen, Ms Soubry and Dr Wollaston's departure will help the ERG to tighten its grip. It also makes life easier for Tory Brexiteers in general. These three MPs had previously threatened to resign if Boris Johnson took over as leader - and now that threat is gone.

Their decision to join Chuka Umunna's splinter group is hardly a surprise, given that they have been going around Westminster together lately pushing for another referendum as if they were already a gang of their own. Now, they have made it official.

Forget the Independent Group's marketing spiel about how it stands for a "different culture". What unites its members is Brexit, and their desire to stop it in another referendum. That is much easier for them to agree on than other subjects such as the economy. Ms Soubry and Mr Umunna used to be on opposite sides over the last Tory Government's austerity agenda, and many of its other policies, but Brexit has brought them together.