Liz Truss must remain Prime Minister into 2023 in order to avoid becoming the shortest serving Prime Minister in British history.

Ms Truss will hold a press conference later today where she is expected to announce her latest mini-budget U-turn.

The Prime Minister, along with Chancellor Kwasi Kwarteng, are set to meet later today before announcing key elements of the budget will be abandoned to reassure the markets.

It follows days of turmoil in the markets amid concerns about the impact of his £43 billion tax giveaway on the public finances.

York Press: PAPA (Image: PA)

The announcement comes amid reports that senior Tories are plotting the possibility of replacing Ms Truss with a joint ticket of Rishi Sunak and Penny Mordaunt, with the Times newspaper also reporting that party grandees are considering replacing her with a “unity candidate”.

Is Liz Truss the shortest serving Prime Minister?

The person who currently holds the title is the Tory statesman George Canning, who spent 118 full days as prime minister in 1827 before dying in office from ill health.

Ms Truss would overtake this number of days on January 3, 2023.

There have been several prime ministers who for various reasons failed to last a year in the job.

They include two Conservative PMs in the past 100 years: Andrew Bonar Law, who clocked up 211 days from 1922 to 1923 before resigning due to poor health, and Alec Douglas-Home, who managed 364 days in 1963-64 until losing a general election.

During the 18th and early 19th century it was not unusual for prime ministers to serve for only one or two years, or to do the job for a short spell on several separate occasions.

Once Liz Truss has passed the 118-day mark set by George Canning, other predecessors she can aim to overtake include the 4th Duke of Devonshire, who was PM for 225 days in 1756-57, and the 2nd Earl of Shelburne, who managed 265 days in 1782-83.

Is Kwasi Kwarteng the shortest serving Chancellor?

Meanwhile, Kwasi Kwarteng has already ensured he will not become the shortest serving Chancellor of the Exchequer in modern history.

Mr Kwarteng has now clocked up 38 full days in the role, eight more than those managed by the Conservative Iain Macleod, who died in office after just 30 days in 1970.