Businesses at a busy office building in Perivale are likely to have to up sticks following an application to turn the building into flats.
Plans have been submitted to change the Research House offices, in Fraser Road, into 41 flats by applicants Research House Dev Co Ltd.
The building is thought to be home to around 200 people working for around 80 companies, with some having been based there almost 30 years.
Opinion is split among the business owners there, with some telling getwestlondon they fear for their future should the application be approved, as they believe they have been given insufficient time to find an alternative home.
But others have insisted they were treated professionally and informed in good time, giving them enough opportunity to find another spot for business.
During consultation for the redevelopment plans, a total of 107 comments were made, with many criticising the proposal, which is due to be determined on September 21.
'We are in a dire position'
One business owner, who requested to stay anonymous, said Research House Dev Co changed the terms of the use of their offices in March so businesses only needed to be given one month's notice to move out rather than three.
He said this put them in a "dire position" after they found out about the application during its consultation only last month, not giving them enough time to find space elsewhere and move their stock out.
The business owner added: "To move out of this place and open at another one, we need at least three months notice to organise, so we are really in a dire situation.
"We have a lot of stock and to move it out would take us two to three weeks of solid work and on top of that we would to find somewhere - it is ridiculous.
"It is all win win for them and lose lose for us."
'Management have been very kind to us'
But another business owner, who also requested to stay anonymous and said she too was first informed of the application last month, said: "I do support the application because I think the owners here and the management have been very kind to us.
"I live in Perivale and I think there are a lot of offices here and I have already given my notice."
Rupwinder Caur, from Pick 'N' Mix Recruitment which has been at the site since 2002, said her business only heard about the application through a fellow business on the site around a month ago.
She said: "We are definitely in the category that feel being done over.
"We heard from another business and at first we laughed, and then he went no this is happening.
"So our directors approached (Research House) and they denied it.
"It is that side of it that a lot of people feel let down by.
"They have left everyone in a bad situation and it really has annoyed a lot of people.
"There was a chap moving out today and he looked gutted.
"It is going to be hard to let our customers know where we are moving to."
She added that they will be able to find an alternative spot, but are disappointed to move having invested into the spot and in letting customers know their location.
Another business owner said he will have to shut his business down because he cannot find somewhere else to run it.
But he said the notice period was changed around a year ago and that he was told of the flats application two months ago.
The shop owner, who requested to stay anonymous, told getwestlondon: "Everyone is in a difficult position, but it is a matter of business and that's business.
"I know that it will affect me. I will probably have to shut my business down and I will have to close because I don't think I can find somewhere else in time.
"They told us two months ago (about the application)."
He added many businesses have already left the site.Research House Dev Co declined to comment.