Next Prime Minister odds: Who could replace Boris Johnson with Defence Secretary and Wyre and Preston North MP Ben Wallace among front-runners

In a sea of resignations, Mr Wallace has remained as Defence Secretary and on Thursday morning took aim at colleagues for their actions that have led to the Prime Minister's downfall.

He tweeted: "A number of us have an obligation to keep this country safe, no matter who is PM.

"The party has a mechanism to change leaders and that is the mechanism which I advise colleagues to use.

"In the meantime, the public would not forgive us if we left these Offices of State empty."

Mr Wallace was rated as a 3/1 favourite with some bookmakers as of Wednesday lunchtime.

Former Chancellor Rishi Sunak, 4/1 and Deputy PM Dominic Raab 5/1 are also high up in the betting.

Sajid Javid, another high profile resignation that marked the beginning of the end for the PM, is 8/1, while Foreign Secretary Liz Truss is 10/1 to get the top job.

Lytham-born Stephen Barclay, who replaced Javid as Health Secretary, is a long shot at 66/1.

Mr Wallace has won admirers in Westminster for his straight-talking and straightforward approach, particularly among Tory MPs who pressed for the UK to increase its defence spending, although cuts to the size of the Army remain a cause for concern.

The 52-year-old, who served in the Scots Guards, remains a key voice in the UK’s response to Russia’s invasion of Ukraine and this increased exposure could assist any leadership bid.

He has consistently supported Mr Johnson, but has pressed the case for increased defence spending.