Cinven, EQT and New Mountain Capital are the final three in the running, according to reports on Sky News, but Grant Thornton will not comment on the deal until it is finalised.

This would be the biggest private equity deal in the UK for the accountancy profession and would shake up the top tier of UK accountancy firms, outside the Big Four with the sixth largest firm ending partnership structure.

This leaves mid-tier firms in a period of major change. Only last week, RSM UK announced plans to merge with RSM US, while Mazars merged with Forvis earlier this year.