The group, made up of businessmen, shareholders and consumers, is set to make an announcement on whether it will appeal the Competition Appeal Tribunal’s decision later today.
MAG wanted the proposed takeover by Lloyds TSB referred back to business secretary Lord Mandelson and then to be heard by the Competition Commission.
The two-day hearing dismissed this argument yesterday.
Should MAG decide to appeal, the case will be taken to the Court of Session in Edinburgh.
HBOS shareholders vote tomorrow on whether the takeover should go ahead.