He gave in after more than 40 ministers quit his government
British Prime Minister Boris Johnson is expected to resign on Thursday, with his office saying he will make a statement to the country.
"Boris Johnson will resign as Conservative Party leader today," BBC Political Editor Chris Mason said on Twitter.
Johnson had been hanging onto power despite the resignation of a string of his top ministers. Johnson finally agreed to step down after one of his closest allies, Treasury Chief Nadhim Zahawi, told the prime minister to resign for the good of the country.
“Prime Minister: this is not sustainable and it will only get worse: for you, for the Conservative Party and most importantly of all the country," Zahawi said in a letter to Johnson. “You must do the right thing and go now.”
"The Prime Minister will make a statement to the country today," a spokesperson said.
Defence Secretary Ben Wallace also called on Johnson to quit but said he would stay in his role to protect national security.
Sun Political Editor Harry Cole said Johnson was aiming to carry on as prime minister until a new leader was chosen later in the summer, a task that can take up to two months