Safeway and Sainsbury's appealed to the government yesterday to increase the limit on Sunday trading hours from its current six hours, in a bid to prevent the mayhem caused at Christmas when December 23 fell on a Sunday.

Shop workers' union Usdaw have reacted angrily to the proposals, claiming that their members could eventually be forced to work on Sundays due to a lack of staff for that day. John Alexander of the Keep Sunday Special campaign said: "We would oppose any extension violently because we have cupboards of evidence of people who have been very badly treated since the act was passed."

Rival supermarkets Tesco and Asda said they saw no need for an extension of Sunday trading hours.