The resignation of Boris Johnson as Prime Minister of United Kingdom opened the race within the Conservative Party to name the person who will succeed him in office. In September, rank-and-file party members will have to choose between Rishi Sunak or Liz Truss to take over as party leader and ultimately rise to the post of prime minister. The contest will not be easy: analysts anticipate a tough campaign between the two candidates. Here we tell you who they are.