Fears have been voiced for up to 180 jobs at the headquarters of Dobbies Garden Centres in Lasswade after speculation the company could be taken over by a rival.
English-based Wyevale Garden Centres is said to have put forward a ?173 million offer to buy Dobbies from current owners Tesco.
Dobbies, founded in 1865, has 35 stores across the UK ? 15 in Scotland, 19 in England and one in Northern Ireland.
Wyevale, which is based in Middlesex, operates 153 garden centres in England and Wales.
It is owned by Terra Firma Capital Partners, founded and led by private equity entrepreneur Guy Hands, whose investment portfolio also includes Odeon and UCI Cinemas and retirement home operator Four Seasons Health Care.
The fear is that if the Wyevale offer was accepted, the headquarters in Lasswade would close.
Tesco is said to want to sell Dobbies as part of its plan to focus attention on its supermarket activities.
It has declined to comment on any bid, but Midlothian SNP MP Owen Thompson has written to senior Tesco management asking about their plans and seeking reassurances about the future of Dobbies.
Mr Thompson said: ?The recent rumours about Dobbies and a potential sale have been troubling, and a matter of concern to my constituents and to me. I understand that Tesco has been clear on its plans to focus on its core supermarket business. However, I would appeal to them to give any purchase offer due consideration before accepting.
?It is the nature of acquisitions that Wyevale will consider rationalising the two businesses and minimising duplication of offices, which would likely result in choosing their existing Middlesex office as their base.
?The loss of almost 200 more jobs would be yet another blow to my constituents at a time when they can least afford it.?
He said he looked forward to hearing from Tesco. ?I hope their response will give reassurance to the people of Midlothian on the future of Dobbies.?
Latest accounts show Dobbies made a pre-tax loss of nearly ?50m on a turnover of ?153m in the year to March 1, 2015.
The company was privately owned until 1997, when it became listed on the stock market. Tesco acquired a majority stake through a ?156m deal ten years later.
Scottish entrepreneur Sir Tom Hunter sold his 29.2 per cent shareholding in Dobbies to Tesco in 2008 for ?36.3m, which allowed the supermarket giant to take the firm private.
Tesco pledged at the time to maintain the Dobbies brand and its Scottish head office.
If the Wyevale bid were to be successful, the two companies would together form a garden centres empire about six times the size of its nearest rival, though the move could lead to an intervention by competition regulators.