British Conservative frontrunner Liz Truss won another heavyweight endorsement today as Tory members began a month of voting to decide the next occupant of 10 Downing Street.

Ms Truss's lagging rival Rishi Sunak vied to make up lost ground with a plan for future tax cuts - and potentially to fund a future women's football World Cup in Britain after England won the European championship.

Ms Truss attended yesterday's final against Germany, and the first victory by any England football team in a major tournament since 1966 wiped Mr Sunak's long-term tax slashing plan off all the front pages except The Daily Telegraph.

The Conservative party contenders are going head to head later today in a members' hustings, in the southwestern city of Exeter - the second of 12 such events before the winner is announced on 5 September.

Mr Sunak, a polished debater, needs to recapture momentum after Ms Truss steamed into a strong polling lead on a platform of immediate tax cuts to address Britain's worst cost-of-living crisis in generations.

Chancellor of the Exchequer Nadhim Zahawi joined other luminaries of Boris Johnson's cabinet in backing the foreign secretary against Mr Sunak, his predecessor in the Treasury.

"Liz understands that the status quo isn't an option in times of crisis," Mr Zahawi wrote in the Telegraph, attacking Mr Sunak's plan to prioritise fighting inflation now, before cutting taxes later.

"We need a 'booster' attitude to the economy, not a 'doomster' one, in order to address cost-of-living woes and the challenges on the world stage," the new chancellor said.

Mr Sunak's resignation from the scandal-tainted Johnson cabinet helped spark a ministerial exodus that forced the prime minister out last month.

As they began receiving postal and online ballot forms, a large chunk of the roughly 200,000 Tory members are said by pollsters to nurse a grievance against Mr Sunak - one shared by Mr Johnson.

The prime minister is not formally taking sides, but has told aides that he intends to give his successor some words of advice, "whoever she may be", the Sunday Times reported.

Despite her endorsements from the likes of Mr Zahawi, Defence Secretary Ben Wallace, former Northern Ireland Secretary Brandon Lewis and Tory centrist Tom Tugendhat, Ms Truss has warned against complacency.

Heading into the Exeter hustings, the foreign secretary has markedly improved in her sometimes robotic public delivery - seen most notoriously in a 2014 speech when she was environment secretary.

Returning to her former field, the Remainer-turned-Brexit zealot promised over the weekend to "unleash" farmers from European Union regulations to improve the UK's food security.

Ms Truss also promised to tackle labour shortages in agriculture, partly caused by post-Brexit restrictions on immigration which have forced UK farmers to leave fruit rotting in fields and to slaughter healthy pigs.

And Ms Truss unveiled a plan on education, vowing that all school students with top grades would automatically get an invitation to apply for Oxford, Cambridge or other prestigious universities.

Ms Truss said that she plans to cut civil service time off, end national pay deals and scrap jobs aimed at increasing inclusion and diversity in the public sector in order to save money.

Ms Truss said: "As prime minister I will run a leaner, more efficient, more focused Whitehall that prioritises the things that really matter to people and is laser-focused on frontline services.

"There is too much bureaucracy and stale groupthink in Whitehall.

"If I make it into Downing Street, I will put an end to that and run a government that focuses relentlessly on delivering for the British public, and offer value to hard-working taxpayers."

Both Ms Truss and Mr Sunak went to Oxford - in her case after attending a state school in the northern city of Leeds that she said let too many pupils down by failing to push them to excel.

Both the contenders have stressed the need for unity once the election is out of the way, aware that the opposition Labour party is riding high in the polls amid the economic crisis and political tumult of Mr Johnson.