It prevents shops over 280 m2 from opening on Christmas Day in England and Wales.
The Act was introduced to the House of Commons by Kevan Jones, MP for North Durham as a Private Member's Bill on 7 January 2004.
Both religious groups and shop worker unions were against the idea of Christmas openings, leading to pressure on the Government to pass legislation to prevent the practice.
In 2006, the Scottish Parliament debated a similar law that would apply to shops in Scotland.
The law was enacted in 2007 and it contained special provisions for New Year's Day retail activities too.