Mackays Stores owner Iain McGeoch has emerged as an ally of entrepreneur Sir Tom Hunter in the latter's court battle with Tesco over Dobbies Garden Centres.

McGeoch, who is a shareholder in Dobbies, has filed an affidavit in relation to the case which, The Herald understands, is supportive of Hunter's position as he tries to block an attempt by the Dobbies board and 65.5% shareholder Tesco to raise £150m in a share issue.

This would leave investors facing a halving of their stakes in Dalkeith-based Dobbies unless they stumped up extra cash. This is a particular problem for Hunter, who would have to spend £44m to keep his 29.5% holding.

Last August, Tesco announced that it had won enough shareholder support to make its £156.6m offer for Dobbies unconditional, a price which Hunter believes undervalued it.

But the size of the stake held by Hunter, who already owns Wyevale Garden Centres and Blooms of Bressingham, prevents the supermarket from delisting the company and enables him to block key resolutions at shareholder meetings.

To maintain this, Hunter's investment vehicle, West Coast Capital, sought a court order this week to stop the share issue, alleging breach of duty at Edinburgh's Court of Session.

Dobbies, which last month acquired the family-owned Sandyholm Garden Centre and Coffee Shop at Crossford in Lanarkshire for £8m, maintains it needs money to finance its expansion plans.

Lord Glennie is expected to rule on the case today or tomorrow.

A spokesman for McGeoch said: "I can confirm Iain McGeoch has submitted an affidavit in this case."

McGeoch's move is particularly notable because he is known for keeping a low profile, despite running a 282-strong clothing chain, recently rebranded M&Co and employing about 3200 people.

The case was further muddied yesterday after Dobbies put out a "clarificatory announcement" denying that the court had been asked to order Tesco to buy West Coast Capital's shareholding.

"The board wishes to clarify that at this stage the court is only considering whether or not to make an order to block the open offer," Dobbies said.

James Barnes, chief executive of Dobbies Garden Centres, did not respond to a request for comment. Dobbies' spokesman Bell Pottinger said it only dealt with London-based media.