53 members of government resigned their positions in recent days.
Boris Johnson expected to step down today - but will remain as British Prime Minister while the Conservative Party elects a new leader.
Boris Johnson is quitting as Tory leader after ministers and MPs made clear his position was untenable.
He will remain as British prime minister until a successor is in place, expected to be by the time of the Conservative Party conference in October.
Mr Johnson will make a statement to the country later today confirming the decision.
The resignation comes after Mr Johnson lost huge support among his ministers and MPs.
More than 50 MPs have resigned from government or party roles since Tuesday night, when the mass exodus was triggered by the resignations of Rishi Sunak and Sajid Javid from the Cabinet.
Mr Johnson had previously said he would "carry on" in office, despite warnings from Cabinet colleagues that this was not sustainable.

Possibility Of Over 10,000 Fatalities As Venezuela Declares State Of Emergency After Two Large Earthquakes
Oil Prices Dip Again As US-Iran Talks Progress
Keir Starmer Resigns As British Prime Minister
US And Iran Pull Out Of Peace Deal Signing Ceremony
US And Iran Say Deal Reached To End War