According to the Daily Telegraph, David Burrowes is one of around 20 Conservative MPs who will break rank and vote against the government on increasing shop opening hours on a Sunday.
Labour has already signalled its opposition to the move, arguing along with trade unions that it will force shopworkers away from their family and religious activities, and deprive them of rest.
The SNP has yet to form an official party line on the issue.
Labour and the SNP, along with the dissident Conservative MPs, would theoretically form a big enough group to defeat the government in a vote on the issue within the next ten days.
David Burrowes told the paper: "It is wrong in principle and wrong in policy - and it was not in our manifesto.
"It is not something that is needed or wanted."
Currently, only a small number of shops are allowed to open for more than six hours on a Sunday.
Supporters of extending Sunday trading hours argue it will boost the economy by encouraging expenditure, provide workers with more hours, and give consumers more flexibility about when they can shop.
The Church of England recently criticised the government's plans to extend Sunday trading hours.