Theresa May will officially step down as leader of the Conservative Party today, APA reports citing BBC.
She became prime minister in July 2016 after the previous PM David Cameron stepped down following the results of the Brexit referendum, meaning she has had the job for almost three years.
Mrs May announced that she was stepping down as the leader of the Conservatives on 24 May.
She will remain an 'acting' prime minister until the next one is chosen.
Lots of Conservative Party members have come forward to say they want to be the next leader.
The candidates need at least eight other MPs to support them in order to be a contender.
The final list of candidates will be confirmed on 10 June.