Three Tory MPs have resigned from the party to join an independent group, set up by former Labour MPs, according to BBC on Wednesday.
The global broadcasting cooperation reported that Anna Soubry, Sarah Wollaston and Heidi Allen wrote a joint letter to Theresa May to confirm their departure.
The three politicians held a jointly press conference, criticising the government for letting the "hard-line anti-EU awkward squad" take over the party.
However the Premier was later quoted by BBC saying she was "saddened" by their decision, but her party would "always offer... decent, moderate and patriotic politics".
The pro-Remain trio will join the new Independent Group - made up of eight Labour MPs who resigned from their party over its handling of Brexit and anti-Semitism - saying it represented "the centre ground of British politics".
At a press conference on Wednesday, Ms Soubry criticised Theresa May for being "in the grip" of the Democratic Unionist Party and the pro-Leave European Research Group, and allowing Brexit to "define and shape" the Conservative Party.