This weekend's popular Filipino festival Barrio Fiesta has been suddenly cancelled after officials refused it a licence over safety concerns.
The council says lack of traffic planning was the main reason council officers, firefighters and police told organisers The Philippine Centre that the party in Lampton Park could not go ahead on Saturday and Sunday.
But Julius Billones, who organised last month's Philippines Independence Day Festival (pictutred) and oversaw last year's Barrio Festival, believes security is the real issue.
He said: "I wasn't impressed with the way last year's event was run, which is why I didn't get involved this time.
"There's going to be a horrible situation this weekend, with coaches from various countries turning up not realising the event was cancelled.
"Businesses have ordered extra merchandise and food and they're waiting to hear when the s1,400 they paid to attend will be returned.
"This would have been the festival's 24th year but we need a more transparent management team to make sure it happens next year.
"We're already in talks about organising a smaller event some time during the next couple of months."
Thousands of people were expected to attend from accross the UK and Europe and police will be forced to turn away visitors who have not heard the bad news.
Stall holders who have paid in advance could be left out of pocket and dozens of planned coach trips from around Europe will have to be scrapped.
A spokesperson for John Laing Integrated Services, which manages parks and libraries on behalf of the London Borough of Hounslow, said: We can confirm that the Barrio Fiesta will not take place in Lampton Park on the weekend of July 19 and 20 because the event has not been granted a licence.
This decision has been made based upon advice from Hounslow Police and London Fire Brigade (Hounslow), who both expressed major concerns over the organisation of the event, particularly the health and safety of those who would attend it.
We have made every effort to support the organisers of the Barrio to meet the obligations needed to obtain the type of licence that's needed for management of large-scale community events like this. However, a number of required licensing conditions have not been met."