Police officers "dread" having to work at the Notting Hill Carnival and an "unacceptable" number are being attacked at the event, a rank-and-file group leader has said.
Chairman of the Metropolitan Police Federation Ken Marsh claimed that an increasing number of criminals want to hijack the celebration, the biggest of its kind in Europe, and turn officers into "professional punch bags".
The latest figures from Scotland Yard on Tuesday showed that of the 454 people arrested on Sunday and Monday, 25 were held for assaulting police. A total of 45 officers were injured.
Mr Marsh said: "This is not a peaceful and fun-loving event that our members look forward to policing. They dread it.
"A seemingly growing number of people appear intent on hijacking this carnival and turning it into a bank holiday battleground, and an excuse for using our members as professional punch bags.
"Last year we had an officer stabbed. This year colleagues were assaulted, abused and spat at. How can that be right? It's completely and utterly unacceptable.
"The Glastonbury music festival had 40 arrests this year. Notting Hill had 10 times that amount. Year after year there are such high levels of violence against police officers and the public at the carnival. And yet year after year nothing changes. Something needs to be done.
"The organisers need to understand that this event cannot carry on regardless. I think many Londoners will wonder whether the significant amount of taxpayers' money spent policing this event is frankly worth it."
Last year Scotland Yard chief Sir Bernard Hogan-Howe wrote to carnival organisers over concerns about the cost of policing the event, the biggest in the force's calendar, saying it was "time to draw the line".
Mr Marsh said more than 7,000 officers worked at the carnival, at a cost of up to £8 million.
Around a million revellers are estimated to attend Carnival each year, while 135,000 music fans went to the Glastonbury festival.
London Ambulance Service treated 1,005 patients at the Bank Holiday procession, mostly for alcohol-related injuries and illness. This was up from 955 last year.
Arrest figures were also up from 407 in 2015, 21 of whom were held for assaulting police.