The SNP just stopped everyone from shopping on a Sunday

The Government has been forced to put on hold its plans to relax Sunday trading laws in order to avoid an embarrassing defeat in Parliament next week.

The Business Secretary Sajid Javid had planned to shake up rules which stop large stores in England and Wales from opening for more than six hours on Sunday with a vote in Parliament next week, but a threat by the SNP to break with convention and vote against the bill has forced him to shelve the new bill.

The SNP has an informal agreement with the Government not to vote on matters that are unrelated to Scotland, but they indicated yesterday that they would be willing to make an exception in this case. Scottish shops are not affected by restricted Sunday opening hours and Scottish workers receive a special "premium" wage if they work on Sundays. The SNP are worried that large chains will stop paying the premium and introduce a nationwide Sunday wage if the rules are relaxed.

Angus Robertson, the SNP's leader in Westminster, welcomed the government's "u-turn" on Twitter, claiming that only allowing Scottish workers to work full days on Sunday would "safeguard" retail staff pay across the whole country.

The Conservatives only have a majority of 17 MPs in Parliament, this means that only around 20 Tory MPs need to rebel in order to put a bill in danger. In the case of Sunday trading, the Government feared there were at least that number who would object to a relaxation of the law on religious grounds.

It's not the first time the SNP have threatened to derail the Government in this way, back in July they forced a vote on fox-hunting in England and Wales to be shelved by threatening to vote on the issue in retaliation for being shown "disrespect" by the Tories.

Despite only having 55 MPs, the SNP are increasingly showing that they are capable of holding the balance of power in Westminster