Labour has called on the Conservatives to repay donations linked to Grenfell Tower’s cladding, as bereaved families accused Lewis Hamilton’s Formula One team of taking “blood money” sponsorship from a firm that made combustible insulation used on the building. The backlash against the sponsorship of Hamilton’s racing car by Kingspan grew on Friday as more bereaved families joined calls for it to be scrapped. Michael Gove, the secretary of state for levelling up, housing and communities, urged Mercedes to reverse the deal, saying he was “deeply disappointed” that it had happened while the public inquiry is continuing. But Lisa Nandy, Gove’s Labour shadow, urged him on Friday to “take the same principled stance” by returning a 2017 donation of nearly £25,000 from a shareholder in Arconic, which made the cladding panels. She welcomed Gove’s comment that “the Grenfell community deserves better” than the sponsorship deal, but said his party should return donations from property developers that had used similar cladding. Gove, whose party has previously said donations are received in good faith and comply fully with the law, has been contacted for comment. The Grenfell Next of Kin group urged the Mercedes team boss, Toto Wolff, and Hamilton not to “sportswash sins” and accused them of being “on the wrong side of history”. Kingspan made some of the foam boards used on the tower, which the public inquiry into the disaster found “contributed to the rate and extent of vertical flame spread”. Its logo will appear on the nose cone of the Mercedes cars at this weekend’s Saudi Arabian grand prix. Hamid Ali Jafari, a member of Grenfell Next of Kin whose father was killed in the blaze, said the deal was “shocking and upsetting” and called on Mercedes and Hamilton to apologise. “If Lewis Hamilton wants to support us, he could put the logo of Grenfell on the car and show that 72 people died and four and a half years later nothing has happened,” he said. Shahrokh Aghlani, who lost his mother and his aunt in the blaze, said: “These people [Kingspan] flouted regulations and didn’t care less. Sport should stand for something in morality. I hope they do the right thing.” The Mercedes AMG Petronas Formula One team has stressed that Hamilton is not involved in the sponsorship deals. The deal was announced with pictures of Gene Murtagh, Kingspan’s chief executive, sitting on one of the Mercedes F1 cars with Wolff. The inquiry has seen emails showing that the day before the first anniversary of the disaster Murtagh instructed his PR team to push ahead with trying to shape press coverage in favour of his firm’s commercial interest, in spite of the sensitivity of the date. After a senior executive urged the firm’s PR consultant to push a story to journalists arguing against banning all combustible materials in external walls, the consultant cautioned against it, saying: “Anything that veers towards the topic of money could be taken badly.” But Murtagh insisted: “We need to push ahead from every angle and without delay.” Ed Daffarn, who escaped from the 16th floor of Grenfell, said the sponsorship deal showed “a callous indifference to the suffering and pain of the bereaved and survivors”. “To see Gene Murtagh sitting on a Mercedes Formula One car is like pouring salt into an already festering wound,” he said. In response to criticism of the sponsorship deal, a spokesperson for Kingspan said it played no role in the cladding system design, and its K15 product constituted approximately 5% of the insulation “and was used as a substitute product without Kingspan’s knowledge in a system that was not compliant with the building regulations”. Mercedes said: “Our partner Kingspan has supported, and continues to support, the vitally important work of the inquiry to determine what went wrong and why in the Grenfell Tower tragedy.”