Police forces would be unable to cope with a repeat of the 2011 riots as a result of budget cuts, the body representing rank and file officers has warned.
Steve White, the vice-chairman of the Police Federation, claimed some officers were being forced to work 14 days straight due to numbers being stretched.
His comments came ahead of the publication of Her Majesty's Inspectorate of Constabulary's latest report on the effects of the Government's austerity measures on the police.
Asked if the police could deal with a wave of unrest on the scale of that in English cities in 2011, Mr White told BBC Radio 4's Today programme: "I don't think they could.
"Recently we have seen deployments of police officers out in Northern Ireland for the G8 and indeed for the problems that they had over there and our officers did extremely well.
"But what you've got to remember, when you lose a large number of officers to a large operation, whether it be in this country or anywhere else, you have got to backfill in order to maintain the service.
"In fact only this week I was being told by representatives from around the country that they have got officers who are having to work stretches of 10, 12, 13, 14 days without a rest day because there simply aren't the numbers there."
He added: "We are not people who will turn round and say 'no, we can't do that' because we are quite often the line of last resort."
But Julia Mulligan, the Conservative police and crime commissioner for North Yorkshire, told the programme Mr White was making the public "unnecessarily concerned".
She said: "The police officers are getting on, doing a good job. Crime is coming down and services are getting better and that's the bottom line."