More than 200 backbench MPs have signed up to oppose a relaxation in Sunday hours.

An Early Day Motion opposing any change in the law now has 218 signatures, and 40 MPs recently attended a cross-party meeting organised by shopworkers’ union Usdaw.

The Save Our Sundays event was also attended by the Association of Convenience Stores. Public affairs manager James Lowman said the extra hours on a Sunday were vital for the survival of small stores: “Our research shows that members’ sales pick up on Sundays and any change could seriously damage the viability of their existence.

“The large number of signatures should be seen as an indication that relaxation of trading hours would be unpopular.”