Traders in Primrose Hill say they are facing a "nightmare" Christmas after Network Rail chose the season to make bridge repairs.
Network Rail must replace the railway bridge which carries the West Coast Main Line over the Regent’s Canal using a "large crane".
Work has already begun and Gloucester Avenue is partially closed, but from December 12 the whole street will be off limits to motor vehicles until January 4.
The most impacted businesses will be Primrose Bakery, grocers Melrose & Morgan, fishmonger La Petite Poissonnerie, specialist jeweller Sweet Pea and The Engineer pub, which will all be hidden from view by blue fencing.
Residents will have to put up with noise and dust from heavy machinery.
A public meeting in early November was so poorly communicated to residents and traders "that only seven people turned up", said local Pam White.
"A subsequent meeting on November 30 revealed the true horror of the closure on Gloucester Avenue," she said.
"Network Rail sent a representative who would neither answer people’s worried questions, provide good information or take any real responsibility for the work and its concomitant disruption."
Effie Kesidou, concierge manager at The Courtyard, which has 39 apartments and five offices, said the works "were confirmed in February but we were only told a few weeks ago".
"There are diversions now so our contractors have to use other roads," she said. "After the 12th we don't know what's going to happen."
She said Courtyard residents had been given parking permits by Camden Council, but that parking in side streets will get very busy.
Martha Swift, owner of Primrose Bakery, said: "This is already having an impact. From next Monday it will be fully closed.
"That means there will be no parking anywhere for customers or delivery workers.
"All of us are independent businesses. We don't have big company backing."
Martha fears customers will go elsewhere and not return.
"I employ 13 people and they rely on me to pay their wages as they have rent, mortgages and children. It's a huge responsibility," she said.
"Network Rail are a huge company, they have a job to do, but they just don't care."
Susana Coenho, manager of La Petite Poissonnerie, said: "Christmas Eve and New Years Eve are our busiest days. They will close us on the 23rd."
She added: "It's an absolute nightmare. We don't want to panic in advance but it's not looking pretty."
At the top of the road, businesses in Regent's Park Road are calling it "a disaster".
Antonis Evangelou, owner of Limonia, said: "Shops are struggling to survive."
Ben Ozman of Ben's grocery store, added: "We're already impacted. The economy has already impacted everything."
A Network Rail spokesperson said it was "sorry to local businesses impacted by the road closure".
They added: "With the footpath still open we’re looking at options to help encourage pedestrians to use the businesses during the road closure.
“While we understand there’s never an ideal time for disruptive railway upgrades, this is essential work which must be done to keep passengers and canal users safe."
He said Christmas was chosen as the "least disruptive time for passengers".
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here