One of the world’s leading golfers, Shane Lowry, is facing growing pressure to end his sponsorship deal with the insulation company Kingspan if it is among firms strongly criticised in the Grenfell Tower inquiry final report due to be published this week. The Ryder Cup player counts the Irish firm as a major sponsor and wears its logo on the sleeve of his golf shirts. He has so far resisted calls from the bereaved and survivors of the 14 June 2017 fire to end the sponsorship arrangement with Kingspan, which made some of the combustible foam insulation used in the tower’s disastrous refurbishment. This weekend he was competing in the FedEx Cup in Atlanta, Georgia, where he was among elite golfers vying for a $25m first prize. Lowry agreed the Kingspan deal one month before the disaster and says on his website he is “thrilled to be getting the backing of one of Ireland’s most successful global companies”. During the Grenfell inquiry hearings, Kingspan was accused by the counsel to the inquiry, Richard Millett KC, of “malpractice … in the development and testing, promotion and sale” of a foam insulation product and “misleading the market about the safety and compliance” of the material for tall buildings. Kingspan admitted to “process shortcomings” but said none were causative of the fire. Ed Daffarn, a committee member of the Grenfell United (GU) group of families, bereaved and survivors, said of Lowry: “We’ve been writing to him for years, saying get this sponsorship off your arm. It’s deeply upsetting and deeply offensive, and he doesn’t reply to us … this is where all that stops.” Conclusions on the extent of Kingspan’s responsibility are likely to form part of the second and final public inquiry report due to be published on Wednesday, alongside findings about Arconic, a cladding company, and Celotex, which made almost all of the combustible insulation used. The Guardian approached Lowry’s management agency, Horizon Sports, for comment. Lowry, 37, has won nearly $27m on the golf course since he turned professional, according to the Spotrac website. In 2021, survivors and bereaved successfully campaigned to persuade the Mercedes Formula One team to drop Kingspan as sponsor of its car, which was driven by the British seven-time world champion Lewis Hamilton. Kingspan also sponsors Ulster Rugby’s stadium in Belfast, and the club resisted pressure from a council in Northern Ireland and the Grenfell United survivors group to end the deal. Last year GU made a presentation to Derry and Strabane councillors that highlighted evidence including emails that showed that when challenged by a potential customer about the suitability of the combustible product for use on high-rise buildings, one member of staff wrote to a colleague that they could “go fuck themselves” and “if they are not careful we’ll sue the arse off them”. In July 2023, when the council made a resolution calling on the rugby club to drop the firm, Kingspan wrote to the council and urged it to change the minutes of a meeting in which a councillor had reportedly said the “Kingspan cladding was the primary cause of the fire spread”. Kingspan said this was incorrect and the principal reason for the spread of the fire was the aluminium composite panels. Phase one of the inquiry concluded that the main cause of fire spread was these plastic-filled cladding panels made by a separate firm, Arconic. But it found that the combustible insulation, most of which was made by Celotex with some from Kingspan, “contributed to the rate and extent of vertical flame spread”. The council did not change the minutes. Kingspan subsequently complained about the GU presentation by Karim Mussilhy, whose uncle died in the fire, and Anthony Roncolato, who was the last resident to escape the tower, in which they held Kingspan responsible for some of the fatalities on the basis that its product was used. Kingspan points to expert evidence to the inquiry that it says shows “the combustibility of the insulation within the facade system on the tower made no material difference” to the disaster. Earlier this year, Kingspan announced it was ending its shirt and stadium sponsorship deal with Ulster Rugby in 2025, saying it was “a natural stepping-off point” after a 20-year relationship. Kingspan declined to comment on the sponsorship issues.