Shopworkers union Usdaw is urging members to persuade their MPs to support a Bill to ban large shops opening on Christmas Day.
The union has pushed for a Private Member's Bill that will stop any shop larger than 3,000 sq ft (280 sq m) from opening on December 25. Usdaw is calling on MPs to vote in favour of the Bill on June 18, when it receives its third reading.
An Usdaw spokesman said: 'We got more than 100 MPs for the second reading, so we're confident that we can get this law passed. There seems to be support from MPs, and no mass industry opposition to it.'