Three Conservative MPs have resigned, saying the party's "failure" to stand up to hardline Brexiteers has forced them to take the decision.
Sarah Wollaston, Heidi Allen and Anna Soubry have joined the new Independent Group.
In a joint letter to Prime Minister Theresa May, the MPs said: "We no longer feel we can remain in the party of a Government whose policies and priorities are so firmly in the grip of the ERG and DUP."
It comes hours after Labour MP Joan Ryan became the eighth MP from the party to resign and join the Independent Group.
The move takes the number of Independent Group MPs to 11.

At least 30 dead in stampede at Haiti’s historic Laferriere Citadel
US-Iran talks pause for now, disagreements remain
Costa Rica receives first group of deported migrants under agreement with US
24 arrested after Kuwait foils terror funding plot
Iraqi parliament elects Nizar Amedi as president
