This is a pretty extraordinary revelation from today at the inquiry.

When the NHBC (the country's largest building control body) threatened to tell the market about Kingspan's combustible insulation was non-compliant for high rises it threatened to sue https://www.insidehousing.co.uk/news/kingspan-threatened-legal-action-against-nhbc-for-raising-concerns-over-non-compliant-insulation-68732

NHBC had said it would start warning contractors (correctly) that use of K15 was not compliant with regs over 18m. Kingspan got its lawyers to seek an injuntion under the defamation act to stop them.

NHBC would later cave in - publishing guidance saying K15 was suitable for use on high rises with various common cladding panels without even any reference to test evidence

The insulation was among the products used on Grenfell Tower, as well as hundreds of other high rises nationwide