Independent traders could be forced to close their shops after being hit with massive hikes in business rates after an error by government inspectors.
Monthly payments for around 20 shops in Ealing Green have shot up by hundreds of pounds after the Valuation Office decided to raise their rates in October.
Now the owners, who are already hit by falling trade, fear they will be unable to meet back-dated demands for cash.
They are preparing to mount a formal challenge to the government agency, which told them the increases were necessary because of a mistake in the previous evaluation three years ago.
Baby e owner Elizabeth Pilgrim, whose monthly rates more than doubled overnight, said: "My blood is boiling about this. A month ago we had a call from the valuation office, and the same inspector who evaluated us originally came back and remeasured.
"I was paying £835 a month for the privilege of having my shop in Ealing, then I got the notification that they wanted £1,700.
"I nearly fell off my chair. I'm a one woman band with two small children, and I'm just trying to make my business work. This is going to have such a negative effect.
"We've got shops closing left, right and centre. At a time like this, they should be giving us rate subsidies. We are going to fight this all the way."
Jim Martinez, of Big Jim's Trims hair-dressers, also had his rates double from around £600 to £1,200. He just opened a new shop in Chiswick which, despite being much larger, costs him only £620 per month.
"Having to pay £500 extra a month is going to really affect us," said Jim, "especially now Westfield has opened.
"I don't know what's going through the valuation officer's mind. I think what's happened is that Starbucks have come in to The Green and they've had a look at it and thought, this is a nice parade, let's up the rate a bit.
"Closing the shop does become a possibility. It's a worrying time, to say the least."
Ealing Broadway BID is working with the traders to help mount a co-ordinated challenge to the rate hikes.
Executive director Steve Breen said: "All the traders along The Green have had at least a 40 per cent increase in their rates dropped on them. That sort of increase is enough to drive these businesses under.
"It's shaping up to be something that will affect the whole of the town centre.
"People are saying that they want independent traders, and Ealing Green is the showcase for the type of shop that we want here. When they get hit with these charges it goes against everything we're trying to achieve."
The Gazette contacted the valuation agency but no-one was available to comment.