limit to 80mph, until the extra death toll this would have caused prompted the plan to be scrapped.

As defence minister in 2013 Hammond attracted criticism by talking about “a real sense of anger among many people who are married” over the gay marriage law. Hammond was later alleged to have likened gay marriage to incest – something he denied.

Rudd rose rapidly under the patronage of Osborne in the last parliament, starting off as his parliamentary aide and ending up in the cabinet.

The 52-year-old is one of the few senior Tory MPs to have won a marginal seat from Labour, taking Hastings and Rye in 2010. After just two years on the backbenches she was promoted by the chancellor, before entering the whips’ office and then heading to theDepartment of Energy and Climate Change.

Her appointment as energy secretary in 2015 was greeted with optimism by green groups, as she is committed to tackling climate change, unlike many of her colleagues on the right of the party.

Rudd struggled to defend the government’s tax credit cuts when confronted by an angry member of the public on the BBC’s Question Time last year.

However, she is regarded by colleagues as a solid media performer, and she was unafraid to take on Johnson in the EU referendum debate.