Survivors of the Grenfell Tower disaster want the French government to intervene so key executives from the maker of the building’s combustible cladding face cross-examination at the public inquiry. They will deliver a message to the French embassy in London on Monday calling for an arcane French law to be waived so employees who worked at Arconic can no longer refuse to give evidence at the inquiry. The French division of the US materials company made the plastic-filled aluminium sheeting already identified as the primary cause of the fire that killed 72 people. But the inquiry has heard that some executives at the company are refusing to give evidence, citing a rarely invoked 51-year-old statute that prohibits people from disclosing commercial or industrial information to foreign judicial and administrative proceedings. It has sparked fury among the Grenfell community. “We can’t let these witnesses hide in France,” said Karim Mussilhy, the vice-chairman of Grenfell United, whose uncle Hesham Rehman died in the fire. “They must face questions here in London. We are urging the French government to do everything they can to bring these witnesses to the inquiry.” The demand will be part of demonstrations by the Grenfell community in London on Monday to mark three and a half years since the fire. Bereaved and survivors will gather at Downing Street to call for the Arconic executives to be forced to give evidence and a ban on any public contracts being awarded to Kingspan, which made some of the combustible insulation used on the tower. Victims’ lawyers allege Arconic knew years before Grenfell of the risks posed by using its panels on tall buildings. But lawyers have told the inquiry that in common with Kingspan and Celotex, which also made combustible insulation, it “sought to market them dishonestly”. The inquiry has already heard that in 2009 Claude Wehrle, one of the former executives said to be invoking the blocking statute, emailed Arconic management with pictures of a high-rise facade fire involving similar panels it eventually sold for Grenfell. It showed “how dangerous PE can be when it comes to architecture”, he said. Arconic has denied wrongdoing and said the main fault lay with those responsible for the refurbishment. A spokesman declined to comment on the impasse, but referred to last month’s statement to the inquiry by its counsel. Stephen Hockman QC said three individuals had taken their own separate legal advice and were “to date at least” declining to give oral evidence. “Whilst the company obviously can’t control whether any witnesses testify, the company remains willing to do what it can to assist the inquiry in working with the French government,” he said. Inquiry officials are in talks with the French government officials and the UK Foreign Office to break the deadlock. The counsel to the inquiry, Richard Millett QC, has said he will empty chair the witnesses if they do not show up, and read out questions they should answer. “If Arconic and its witnesses seek to stand on their strict legal rights and refuse to come to give evidence, that is a matter for them,” he said. “They may find that the bereaved, survivors and relatives, other core participants, and indeed the public generally take a dim view of their conduct.” The French embassy in London has been contacted for comment.