London businesses struggling with sales due to the cost-of-living crisis are calling on the government to relax Sunday trading rules in the capital.
The Knightsbridge Partnership Business Improvement District (BID) is in favour of longer opening hours, estimating it would generate £300m a year.
Liberal Democrat London Assembly members also say the change could increase tourism and employment.
The government says there are no plans to change the law.
Sunday Trading regulations date back to the Sunday Fares Act of 1488, when the last day of the week was traditionally a religious day of rest.
In 1994 this changed when the Sunday Trading Act was brought in, allowing small shops to open for as long as they want on Sundays - but large shops over 3,000sq ft (280sq m) are still only allowed to open for six hours.
Steven Medway, CEO of the Knightsbridge Partnership BID, said: "We did a report a few years ago, where we estimated that we would generate an extra £300m a year and generate 2,000 jobs if the relaxation of Sunday trading was implemented."
He said stores like Harrods turn away "many visitors" on Sunday evenings.
"They travel round the world, [and] see other places like Paris who have relaxed their laws most recently, and New York that has never had this issue to start with."
However, small business owners said they worry about competition on Sundays if larger stores are able to open for longer.
"It is a very popular day on Sunday for us. We do a couple of thousand in business... but that will not happen if all the bigger supermarkets open," said Chandra Goyal, who owns the Central Food and Wine shop in Soho, central London.
"We're a small business so we cannot beat supermarket prices," he explained.
In Scotland there has never been any legislation preventing Sunday trading and shops can open for as long as they want.
Liberal Democrat member of the London Assembly, Hina Bokhari, told BBC Politics London changing the law would be a "boost for the economy" and would in turn increase tourism and employment in the capital.
'Why can't London?'
"We've already seen that in Scotland it's been very successful and we haven't seen that kind of impact on the smaller businesses.
"If other cities are doing it, why can't London?," she said.
Ellie Reeves, Labour MP for Lewisham West and Penge, said any change needed to be carefully thought out, for example ensuring workers kept a work-life balance.
"We all want to see our high streets revitalised but I'm not sure this is the right solution," she said, arguing business rate reform, policing in retail areas and measures to combat empty shops could be more effective.
Sir Bob Neill, Conservative MP from Bromley and Chislehurst, said in his personal view "you have to update laws to reflect how we live our lives now" and suggested a pilot scheme at peak times of year such as Christmas, or in certain parts of London, could be effective.
However, he stressed shops and staff would "need some sort of protections to make sure they are not overburdened".
A government spokesperson said: "There are currently no plans to change the Sunday Trading Act."
You can watch Politics London in full on Sunday on BBC One, or on BBC iPlayer.