Sainsbury’s and Asda will today lodge an application with the Competition Appeal Tribunal for a judicial review of the Competition and Markets Authority’s investigation into their proposed merger.

The grocery giants are requesting a review of the timetable and process of the CMA’s ‘phase two’ investigation as they believe “the current timetable does not give the parties or the CMA sufficient time to provide and consider all the evidence given the unprecedented scale and complexity of the case”.

Sainsbury’s and Asda said they have made “repeated requests” for additional time.

“Specifically we have asked the CMA for an additional 11 working days over the Christmas period to respond to a large amount of material recently provided to us,” Sainsbury’s said in a statement to the Stock Exchange.

“We are confident in the merits of the deal and our ability to deliver the synergies. By bringing our two businesses together, we will invest further in range, quality and customer service, while lowering prices and reducing the cost of living for millions of UK households.”