There is to be a second judicial review of the government's decision to grant planning permission for a John Lewis store near Lisburn, County Antrim.
John Lewis was given planning permission to locate at Sprucefield
Plans for the Sprucefield store and 29 adjoining units were given the go-ahead more than two years ago, overturned, resubmitted then approved again.
In the High Court, Lord Justice Girvan granted leave for a new review.
He said a former NIO minister had acted contrary to the recommendations of his own officials in approving the plan.
He said David Cairns, who held the environment portfolio, had also failed to give reasons for doing so.
The opponents of the scheme include the chambers of commerce in Lisburn and Belfast and a group of shopping centres including the Rushmere in Craigavon, Bow St Mall in Lisburn and the new Victoria Square in Belfast.
The legal action has already cost the taxpayer at least £200,000.
The developers, Westfield, say the scheme could create up to 2,000 jobs.