Opponents of the proposed retail expansion at Sprucefield, near Lisburn, won the right to mount a new legal challenge on Friday.
Rival traders claim the Department of Environment should have placed newspaper adverts about the scheme.
The inquiry is likely to be adjourned until after the High Court proceedings are resolved later this year. The full judicial review will be heard in September.
-- Advertisement --
MP for the area, Jeffrey Donaldson said that the point of a public inquiry was to allow all objectors and people to voice their opinion on the scheme.
"These opponents are not acting on behalf of the public, really they just want to stop John Lewis coming to Northern Ireland," he said.
"This is a major investor, it would create over 1000 jobs in Northern Ireland and the message going out is that Northern Ireland is closed for business."
Glyn Roberts, Northern Ireland Independent Retail Trade Association chief executive, said his members object to the location of the store.
He said: "We welcome the inquiry and all sides get their day in court and to have their say."
The trading association argue that the department store along with 19 other stores would increase out-of-town shopping.
"Our preference would've been for a town centre location but I think a decision needs to be made and the traders, and John Lewis need closure," Mr Roberts added.
The owners of the retail centre have been trying to get approval for the store since 2004.
(NS/GK)
