The government faces a possible defeat over its plans to shake-up Sunday trading laws as the SNP is set to reject the proposals.

MPs are due to vote on the controversial plans in Parliament today, but opposing parties are set to block the new laws or force the government to water them down. 

The SNP said previously it would back the plans but now its 54 MPs are expected to vote against.

The party is concerned that premium Sunday pay rates for shop workers in Scotland would not be protected if the new laws were passed. 

More than 20 Tory MPs are also threatening to oppose the new laws, which would be the biggest change to Sunday trading laws for 20 years.

Labour is also opposed to the plans as it says the current rules work well and allow shop workers to spend time with their families.

The Association of Convenience Stores is strongly opposed to the plans, while the BRC has called for safeguards if the law is changed.

Under the new laws for England and Wales, councils would be given the power to allow shops larger than 3,000 sq ft to open longer than the current six-hour limit.

The government could look to reduce the number of Tory rebels by accepting an amendment from former environment secretary Caroline Spelman, which would allow cities with significant numbers of tourists to opt out of the current laws on Sunday trading, it was reported. 

Retailers will also have their eyes on Parliament next week when Chancellor George Osborne unveils the results of the government’s business rates review in his Budget speech.