Private equity-backed groups, such as restaurant chains PizzaExpress and Prezzo, or Merlin Entertainments, the owner of Legoland and Alton Towers, have so far been largely unable to access state-guaranteed loans because the industry's debt-heavy financial model has put them at odds with EU state aid rules.

The new rule will allow them to restructure the balance sheets of the companies they own in order to pass the EU's eligibility test.

The move will be a lifeline for struggling companies in the retail, leisure and hospitality sectors that are owned by buyout groups. However, it is likely to prove controversial, since it will allow government funds to go to companies that in some cases have large debts, leaving them vulnerable, and since private equity firms are sitting on record sums of money raised for new deals but not yet spent.

The British Private Equity and Venture Capital Association, which has been lobbying for the reform, said it would review the revised guidance and discuss it with its members.

Ministers are scrambling to extend additional support for businesses as the UK faces further restrictions that will again hit employers this autumn, in particular on the high street, given new 10pm curfews and guidance that people should work from home where they can.

On Thursday, Chancellor Rishi Sunak confirmed the extension of the £58bn loans programme until the end of November as well as greater flexibility over repaying loans. The private equity industry has been fighting for ministers to relax the rules to allow otherwise sound businesses secure emergency funds from banks backed by state guarantees.

Private equity firms had invested heavily in leisure, hospitality and retail before the pandemic: Blackstone owns Merlin Entertainments while casual dining chains Café Rouge, Prezzo and Byron are owned by Epiris, TPG and Three Hills respectively.

Many of these companies will be hit hard by new rules requiring 10pm closing times.

The industry's lobbyists have been arguing that hundreds of thousands of people work for the companies they own, with jobs at risk if they cannot access the state-backed loans that are available to other businesses.

• MERLIN ENTERTAINMENTS LIMITED