Morrisons must not be taken over for the ‘wrong reasons’, warns L&G

Apollo is also considering an offer for the chain. It has not yet made an approach to the board of Morrisons and said there is no certainty that an offer will materialise.

Separately, investors are waiting for the next move from another US buyout company, Clayton, Dubilier & Rice (CD&R), which is working with former Tesco boss Sir Terry Leahy and made an initial £8.7bn offer that was revealed a fortnight ago.

Another top 20 Morrisons shareholder said they expect the bidding to go up.

Fortress has provided assurances that it will not embark on a “major” sale-and-leaseback exercise if it buys Morrisons.

Its offer is being made with the Canada Pension Plan Investment Board and the property arm of Koch Industries, America’s biggest private company.

Morrisons’ chairman Andrew Higginson has launched a charm offensive this week as it needs 75pc of investors to approve the Fortress deal.

He was in talks with Minette Batters, president of the National Farmers’ Union, over the weekend to soothe concerns that taking the supermarket private for the first time since 1967 would pile pressure on its members’ margins. Mr Higginson has also asked to meet Kwasi Kwarteng, the Business Secretary.

Ms Batters said on Monday that she was encouraged by early pledges from Fortress to preserve Morrisons’ relationships with suppliers.

“Sourcing from British farms has long been part of Morrisons heritage and it is reassuring that the potential buyer wishes to continue to uphold these core values going forwards,” she said.

Shares in Tesco and Sainsbury’s also rose on Monday.