Dr Sarah Wollaston MP, alongside two other Conservative MPs have decided to resign the party whip.
In a co-written letter addressed to Theresa May, Sarah Wollaston, MP for the Totnes constituency, Anna Soubry MP, and Heidi Allen MP, said they could no "longer remain in a remain in the party of a Government whose policies and priorities are so firmly in the grip of the ERG and DUP."
Dr Wollaston said on social media: "From the outset, I have made the case for a centrist, moderate and outward looking approach to our politics.
"I assure you that I will continue to take that approach but will now do so as an independent MP."
More on this story in Friday’s paper.