The Prime Minister said water cannon – until now only ever seen in the UK in Ulster - will be available at 24 hours notice

to deal with the “despicable violence” being carried out in cities across the country.
And in a sign that other more draconian crowd control measures will now be at the disposal of the police he said: “We will do whatever is necessary. Nothing is off the table.”
In his strongest comments yet on the perpetrators of the violence, Mr Cameron said: “There are pockets of our society that are not only broken, but frankly sick...It is a complete lack of responsibility in parts of our society, people allowed to feel that the world owes them something.”
Water cannons have been used this summer by police in Ulster and have been a regular sight at disturbances in the province. But despite calls for it to be used on the mainland – including after last year’s student riots in London – ministers have always ruled it out.
Mr Cameron spoke after chairing a meeting of the Cobra emergency committee. He rebutted criticisms from Boris Johnson about proposed cuts in police numbers. The London Mayor today caused anger in Downing Street by saying London’s police strength should not be lessened.