Boris Johnson will face a series of challenges in his first 100 days as prime minister, culminating in the Brexit deadline on October 31.

Here are some of the key events:

โ€“ July 24 Theresa May will take her final session of Prime Ministerโ€™s Questions before offering her resignation to the Queen. Mr Johnson will then take over in No 10.

Forming a new Cabinet will be among his first tasks. He will seek to promote loyalists while maintaining command over Tory MPs after a series of pre-emptive resignations.

(PA Graphics)
(PA Graphics)

โ€“ July 25 The final sitting day in the Commons before it breaks for the summer recess.

โ€“ August 1 Brecon and Radnorshire by-election. Tory candidate Chris Davies is seeking to regain the seat he was ousted from by a recall petition triggered in the wake of his conviction for submitting false expenses claims. If he fails, Mr Johnsonโ€™s working majority in the Commons will be cut to just one.

Christopher Davies petition
Chris Davies (Victoria Jones/PA)

โ€“ August 24 G7 Summit in Biarritz. The new prime ministerโ€™s first appearance at a major global summit. Donald Trump will be among the world leaders at the gathering, potentially providing the opportunity for a meeting with the controversial US president in an effort to highlight the importance of the special relationship and a future trade deal.

โ€“ September The UN General Assembly meeting in New York will provide another opportunity for Mr Johnson to appear on the global stage and set out his vision for the countryโ€™s place in the world.

โ€“ September 29 to October 2 Conservative Party Conference. The gathering in Manchester will be a key test of the new Tory leaderโ€™s ability to unite the party and provides a platform to use their closing speech to address the nation.

โ€“ October 31 The deadline for reaching a Brexit deal. Unless there is a further extension, this will be the UKโ€™s last day as a member of the European Union and it will leave, with or without an agreement.