Sainsbury’s and Asda say their planned merger will save them £1.6bn in cost savings and allow them to pass on £1bn in price cuts to savers.
The two supermarket giants are battling to convince the Competition and Markets Authority (CMA) to allow them to join forces, a move that would see them leapfrog Tesco to be the biggest in the country.
The CMA said last month a merger would see higher prices and less choice.
It said it could block the deal.
The CMA said that if it did allow the merger to proceed, it could force the sale of a large number of stores or even one of the brand names.
On Tuesday, Sainsbury and Asda’s joint statement said the CMA’s provisional findings contained “significant errors”.
In a robust statement, it criticised the CMA’s threshold at which concerns were triggered. It said this was set at an “unprecedentedly low level”, which, therefore, generated an unreasonably high number of areas of concern.