Fearful North Kensington traders believe the new £1.6billion Westfield shopping centre - set to open in a fortnight - will have a 'terrible impact' on historic Portobello and Golborne markets.
Shopkeepers and stallholders, already hit by the western extension to the Congestion Charge, are concerned that shoppers will flock to mammoth Westfield shopping centre, due to open near the border of the Royal Borough and Shepherd's Bush on October 30.
Jani Singh, whose family have owned the Cash and Carry shop in Golborne Road, North Kensington, since 1978, believes his business will struggle to survive.
He said: "At least six businesses along this road have closed in the last month because larger supermarkets are taking away our trade. We're suffering already even though Westfield hasn't opened yet, so I think it will have a terrible impact on the area.
"Portobello market used to be the number one place in the country for people to go shopping, but slowly we're all being forced to close. It's nothing like it used to be, but how can we compete, when these supermarkets keep opening up all around us?"
Holland Park Avenue shops are also set to be affected by the new complex, which will contain up to 265 stores.
Manager of Lidgate Butchers in Holland Park Avenue, Danny Lidgate, said it might cause new traffic problems.
"The Congestion Charge hasn't done us any favours and we're worried Westfield might make traffic heavier," he said. "The A40 is quite congested and it might put people off coming to us.".
Nearby businesses in Hammersmith and Fulham also expressed concern. Stallholders at Shepherd's Bush Market fear that fellow traders, in competition with the store, will be forced off patch.
A Westfield spokeswoman said: "Westfield London will attract local residents and visitors from across London and beyond, greatly increasing passing trade in the area as people use public transport to and from the centre.
"Rather than competing with the distinctive, and well-established Shepherd's Bush Market, Westfield London will offer something different - a lifestyle and leisure experience that will complement the existing local shops."