Liz Truss, the most popular cabinet minister among Conservative voters, has been handed a significant promotion and become the first female Tory foreign secretary. Described by supporters as “one of the only true capitalists left in the cabinet”, Truss was said to have raised private concerns about the national insurance rise unveiled by the prime minister last week, and this week she spoke in favour of “enterprise” instead of “statism”. In a speech to the Policy Exchange thinktank, described by a source as an appeal to “Lidl Tories”, she said the Conservative party should embrace free enterprise instead of “inexorably growing the size of the state”. After two years leading the Department for International Trade, Truss has become well versed in articulating a post-Brexit vision of “global Britain”. Announcing trade deals with her signature upbeat patriotism, she is liked by colleagues who view her as hard-working and focused – so much so that some have come up with the slogan: “In Liz we Truss.” The new foreign secretary’s first international trip is expected to be as early as next week, when she will accompany Boris Johnson to the UN general assembly meeting in New York. High on the agenda will be “rekindling our relationship with the US”, a senior Tory said after Britain felt left in the dark by Joe Biden’s administration during the chaotic withdrawal from from Afghanistan. Despite the pandemic, it will not be her first trip overseas this year: besides her predecessor Dominic Raab, Truss is the only other cabinet minister known to have taken a holiday abroad this summer. Back home, MPs said she “should certainly get on much better with Ben Wallace” in reference to the row between the defence secretary and Raab over the handling of the evacuation from Kabul. Iain Duncan Smith, the former Tory leader who previously served in cabinet with Truss, said she had been “one of the more robust people on China, and I hope that now she will take to the Foreign, Commonwealth and Development Office that robust attitude and make it clear that we can’t reward this Chinese regime with more trade deals”. He hoped her enthusiasm for entering the Pacific trade partnership known as CPTPP would continue, pushing for the UK to “project ourselves post-Brexit to stop China becoming completely dominant” in the region. Some were surprised that Johnson appointed someone widely talked about as a future leadership contender to one of the four key offices of state. While Raab tried to hold on to his senior cabinet post on Wednesday, he was unsuccessful – and ended up being moved to the Ministry of Justice, to replace Robert Buckland, though he was given the consolation prize of deputy prime minister. Some government insiders suggested it was a move to stymie Truss’s opportunity for political manoeuvring by giving her more diplomatic responsibility that will mean she can be less outspoken on domestic policy. However, a senior Whitehall official who worked with Truss at the trade department said “a lot of people don’t take her as seriously as they should”. “She’ll bang the drum for global Britain even more vigorously than she did at trade – which isn’t a bad thing at all,” they said, adding she would likely be “more hawkish on China” and pointed to recent outspoken comments on intellectual property theft and forced labour in China’s Xinjiang province. MPs said Truss’ star was likely to rise further in the new role. “She’s just kept her head down, got on with the job and delivered – and she’ll do that again,” one said. Another added: “She takes no shit.” Truss will keep her existing role as minister for women and equalities, a blow for some Tories who viewed her as too keen to appear “anti-woke” at the expense of supporting greater rights for transgender people. One said it was a “missed opportunity” and she would be unable to devote the time the role deserved.