In his own words, Rishi Sunak is a Thatcherite, a Brexiteer, and a tax cutter.
He is private school and Oxford educated, and made millions as a City banker before joining the world of politics.
Yet, in the race to be the next leader of the Conservative Party – and prime minister – Sunak has emerged as the enemy of the Tory right wing.
As chancellor during the peak of the coronavirus pandemic, Sunak was a big spender, digging deep to prop up the economy during lockdown.
To foot the bill, Sunak shied away from extra borrowing, choosing instead to hoik the tax burden to its highest level in 70 years in order to balance the books.
It is this that has driven the "true blue" Tories to back Liz Truss in the race to Number 10.
Despite being a Remainer and a one-time Liberal Democrat, Truss is the self-styled "true Conservative" contender.
She has won supporters on the right with her promise of a new economic plan, consisting of so-far uncosted tax cuts amounting to tens of billions of pounds.
Sunak has made his opposition to this approach clear, warning it could make the UK's inflation crisis worse.
But who is Rishi Sunak, and why exactly has the Tory right turned against him?
Sunak was born in Southampton in 1980 to East African Indian immigrants who arrived in the UK in the 1970s.
He went to one of the UK's most expensive private schools - Winchester College - before proceeding to Oxford to study politics, philosophy and economics, followed by Stanford University in California, where he gained an MBA.
He subsequently worked in banking before entering politics in 2014 as the MP for Richmond (Yorkshire).
After working in junior ministerial roles, Sunak became a household name when he was appointed chancellor following Sajid Javid's resignation in February 2020.
Sunak lives between Kensington, London and his constituency home near North Allerton, Yorkshire with his two children and wife Akshata Murty - daughter of multi-billionaire Indian tech giant, Nagavara Ramarao Narayana Murthy.
The pair have a net worth of £730m, making the Sunday Times Rich List in 2022. Sunak's vast wealth has been used by his critics to claim he is too rich to be in touch with voters.
Sunak and Murty came under fire earlier this year after it emerged Murty was registered as non-domiciled, a legal - but sometimes controversial - tax arrangement which means she pays British taxes on earnings in the UK but not from overseas. The system can be used to reduce the amount of tax a person pays in the UK.
After intense backlash, she gave up her non-dom status, saying it was at odds with "the British sense of fairness". Sunak also faced backlash after it emerged he had held a US green card while serving as a minister.
Sunak's time as Chancellor made him an enemy of the Tory right, who said his policies on taxation and spending are un-Conservative.
Their discontent was stoked as the Treasury spent more than £350bn on policies to deal with the pandemic after the UK was plunged into strict lockdown restrictions weeks after Sunak was appointed chancellor.
Sunak announced a package of measures to protect jobs and businesses, including the furlough scheme, Eat Out To Help Out, VAT cuts, and the business recovery loan scheme.
To foot the pandemic bill, the former chancellor introduced a number of tax hikes - including plans to increase corporation tax to 25% from 2023; freezing income tax thresholds; and hiking national insurance contributions by 1.5 percentage points.
In May this year, he fanned the flames of disapproval on the Tory right wing by introducing a windfall tax on major oil and gas companies as part of measures to tackle the cost of living crisis.
Combined, it leaves Brits saddled with the highest tax burden in 70 years. So far the only pledge Sunak has made on tax cuts is to look at knocking 1p off income tax in 2023.
The Tory right claim all of this has stifled growth.
Most are therefore backing Liz Truss, who is promising - largely unfunded - tax cuts, including reversing the national insurance hike, reversing planned corporation tax increases, and suspending the green levy on energy which makes up around 8% of an energy bill.
Sunak's high-spending approach even led Johnson ally and Tory right winger MP Peter Bone to brand him a "socialist chancellor".
However Tory stalwarts, such as former chancellor Ken Clarke, have defended Sunak's fiscal stance – arguing the country cannot afford to cut taxes due to the economic fallout from the pandemic.
A fractious relationship
It's not just policy that has antagonised the Tory-right. Sunak has also made enemies among dyed-in-the-wool supporters of Boris Johnson as a result of his fractious relationship with the outgoing prime minister.
His ambitions for the top job have been an open secret since his promotion to the post of chancellor and caused friction between Number 10 and Number 11, especially when Sunak pushed back against his boss's desire to cut taxes and increase public spending.
In his resignation letter, Sunak said irreconcilable differences with the PM over the economy motivated his decision, saying "the public rightly expect government to be conducted properly, competently and seriously."
Hitting back, in his farewell speech to MPs in parliament Johnson said: "I love the Treasury - but, remember, that if we’d always listened to the Treasury we wouldn’t have built the M25 or the Channel Tunnel."
Truss is now seen as the Johnson continuity candidate by the Tory right, with most of the outgoing PM's most vehement loyalists backing her campaign.
How to deal with a problem like inflation
The question of how to best manage with the cost-of-living crisis has been a key division between Sunak and the right of his party, which backs extensive tax cuts as a means of encouraging growth.
Sunak has been clear he believes slashing tax will worsen inflation, and that the nation's finances are not in a state to do so.
Truss's less-than-subtle fiscal pitch to the Tory right involves tax cuts to the tune of tens of billions, with the stated intent of putting "cash back in people's pockets".
Sunak, on the other hand, has stuck by his existing plan.
In May, as chancellor, he announced a £15bn package of measures to help with the crisis amid soaring energy bills, spiking inflation, and warnings from experts that more than a million people would fall into absolute poverty without extra support.
Since the launch of his leadership bid, Sunak has proposed no additional measures to address what is now being referred to as a "winter crisis".
What he plans to do as prime minister
While his campaign has been policy-light so far - mainly focusing on what he would not do - according to The Times Sunak is set to announce a long-term tax cuts timetable and new immigration plans.
Elsewhere, he has suggested he would reverse the trend of "clumsy, gender neutral language" which he argues erases women.
He has also said he would seek to introduce tougher sentences on criminals who do not turn up for their trials, as well as overruling parole boards if particularly dangerous offenders are set to be released.
Watch: Rishi Sunak says Liz Truss would cost Conservatives the next election