Labour has called on the government to explain why it claimed Liz Truss hosted a £3,000 lunch at a private members’ club because it was available at short notice, when correspondence later showed that she had insisted on the venue. In a letter to the international trade minister, Anne-Marie Trevelyan, Labour also asked why Truss, Trevelyan’s predecessor in the role, had overruled civil servants’ concerns about the cost of the members’ club, owned by a Tory donor. The correspondence, disclosed by the Sunday Times, showed that Truss, now the foreign secretary and a favourite to succeed Boris Johnson, “refused to consider anywhere else” and asked that public funds should pay for the event with Joe Biden’s trade representative. According to the correspondence, Truss, then the trade secretary, “explicitly asked that we book 5 Hertford Street”, owned by Robin Birley, a £20,000 donor to Boris Johnson’s leadership campaign and the half-brother of Zac Goldsmith, the environment minister. The venue agreed to reduce the bill to £1,400, but on condition of immediate payment – which meant civil servants had to use an emergency process to pay up straight away. In the letter to Trevelyan, Labour’s shadow international trade secretary, Nick Thomas-Symonds, said that when the Mail on Sunday asked about the event in November, “it is understood that the department’s own press office stated that the reason for such expense was due to it being organised at ‘short notice’ and therefore down to availability”. He continued: “However, in correspondence it showcases that it was not down to short notice, but the insistency of the former secretary of state.” As well as seeking clarification on this, the letter asks Trevelyan when she learned of the dinner, why the venue was chosen and why Truss overruled civil servants, and whether the club had been used for other events. “These revelations showcase the complete lack of transparency and accountability of such decisions,” Thomas-Symonds wrote. “What we see from this government is a flagrant abuse of the powers that have been given to them.” Before attending the event with US trade representatives, a civil servant described the club as “obviously incredibly expensive and more than I understand we’d usually expect to pay for such a venue”. It was requested, the official wrote, as the private dining room was “of the appropriate size and standing”. Truss and her companions drank two measures of dry gin; three bottles of Pazo Barrantes Albariño, a Spanish white wine, costing a total of £153; and two bottles of the French red Coudoulet de Beaucastel, costing a total of £130, it was reported. Department for International Trade officials argue that the booking was made at short notice, just a day before the event, and that alternative venues might not have been cheaper. A spokesperson for the department said: “This was a diplomatic working dinner attended by the previous international trade secretary, senior UK officials, and US counterparts from our largest single trading partner.” • This article was amended on 4 January 2022 to correct details of the drinks reportedly ordered at 5 Hertford Street. An earlier version also erroneously said the Truss correspondence was obtained by the Sunday Times in a “leak”.