Retailers’ hopes that Sunday trading rules would be relaxed for the Boxing Day Sales have been dashed by the Government.

The decision is likely to cost the stores sector at least £50m in lost sales in London’s West End alone.

Stores will only be able to trade for six hours on Boxing Day, the launch date for many retailers’ post-Christmas clearance promotions, the Daily Telegraph reported.

Store chiefs including Arcadia owner Sir Philip Green and Debenhams chief executive Rob Templeman had lobbied for a one-off change and won the support of London mayor Boris Johnson.

Christian groups opposed the idea and the Government turned a deaf ear to retailers’ pleas. In response to a question from the Bishop of Gloucester, business minister in the House of Lords Baroness Wilcox said: “I can confirm that the Government have no plans to change the rules on Sunday trading at the moment.”