<a href="https://www.thenationalnews.com/tags/liz-truss/" target="_blank">Liz Truss</a> will be the UK’s next prime minister unless she “fouls up in some spectacular fashion” in the last two weeks of <a href="https://www.thenationalnews.com/tags/conservative-leadership-race/" target="_blank">the Conservative leadership contest</a>, one of Britain’s most respected polling experts has said. Sir John Curtice told <i>The Times </i>he would be “extraordinarily surprised” if Ms Truss fails to defeat her rival <a href="https://www.thenationalnews.com/tags/rishi-sunak/" target="_blank">Rishi Sunak</a> when results are announced on September 5. The confident prediction came despite fresh scrutiny of Ms Truss’s economic policies after gloomy budget figures raised doubts about her tax-cutting promises. The government borrowed about £4.7 billion ($5.6bn) more than expected in July alone, the Office for National Statistics said, calling into question the £30bn of so-called fiscal headroom that Ms Truss is relying on to fund tax cuts. Asked whether Ms Truss’s sums still added up, one of her supporters, Conservative MP Jake Berry, said on Friday that the headroom could rise because of economic growth generated by tax cuts. “It is my view that Liz Truss’s plan to cut taxes, to help ordinary working families, is the right one to create economic growth,” he told Sky News. Tax and spending has emerged as the key dividing line in the context, which is playing out against the backdrop of <a href="https://www.thenationalnews.com/business/economy/2022/08/17/uk-inflation-rate-rises-to-101-as-cost-of-living-soars/" target="_blank">the highest inflation in 40 years </a>and growing concerns over how British households will cope this winter. Ms Truss, the foreign secretary, has put her focus on tax cuts, contrasting her promises with the tax increases overseen by Mr Sunak during his two years as chancellor of the exchequer. Mr Sunak has described Ms Truss’s plans as unfunded and said he would prioritise targeted support for people who struggle to pay their bills in the winter. Ms Truss was separately accused of showing her “true colours” in a resurfaced policy paper in 2009, co-written by her, which called for deep spending cuts including lower pay for doctors and the end of universal child benefit. Her campaign distanced itself from the paper after it was unearthed by TalkTV, saying Ms Truss did not support all the ideas of her co-authors. But Labour Party deputy leader Angela Rayner said: “Liz Truss’s track record shows her true colours … out of touch and out of step with the public. “Her desperate attempts to distance herself from her own views will fool no one.” The contest is nearing its end with the ninth out of 12 Tory hustings set to take place in Manchester later on Friday. Ms Truss made her pitch to Manchester voters by promising to revive plans for a so-called Northern Powerhouse rail link, after they were watered down by the previous government in which she served. She said the “defining mission” of her government would be to increase economic growth by cutting taxes and using post-Brexit freedoms to deregulate the economy. Mr Sunak meanwhile published a plan for young people including help to buy property with cheaper mortgages and reforms to education such as “boosting the prestige” of vocational courses. Voting ballots were sent out in early August and many of the party’s roughly 200,000 members are believed to have voted already, with polls showing Ms Truss in a commanding lead. Whoever is declared the winner on September 5 will take over from <a href="https://www.thenationalnews.com/tags/boris-johnson/" target="_blank">Boris Johnson</a> as prime minister the following day.