Policing costs for two West Yorkshire protests top £1m
The cost of policing two demonstrations by the English Defence League (EDL) and Unite Against Fascism (UAF) topped £1m for West Yorkshire Police.
Police authority chairman Mark Burns-Williamson revealed the cost of policing the events in Leeds in October 2009 and Bradford in August 2010.
He said he has written to the Home Office suggesting a limit on the numbers allowed at future protests.
The Home Office said it has no plans to restrict the right to demonstrate.
In the Leeds 2009 demonstation about 900 English Defence League (EDL) supporters staged a protest against Islamic extremism in City Square.
Meanwhile a rival demonstration of up to 1,500 Unite Against Fascism (UAF) supporters took place about 300 metres away.
Four people were charged with public order offences.
'Implications for freedom'
In Bradford last year 14 protesters were arrested after skirmishes broke out.
Mr Burns-Williamson said: "We had the Bradford riots in 2000, the cost of that was £13m, that wasn't a demonstration but we were badly impacted.
"We had only just recovered in building up some of our reserves in recent years.
"The figure (for the two recent demonstrations) does not take account of all the opportunity costs, planning and intelligence, so in actual fact that cost if you really wanted to quantify it would be much more."
Mr Burns-Williamson said the authority's letter to the Home Secretary had made suggestions for future legislation on protests including a limit on the number of people who can take part in a protest.
He said: "Our letter was in the context of the EDL, but it could apply to similar demonstrations. If we went down that path I accept it would have implications for the freedom of movement and the history of this country. It would have to be very specific based on assessment and intelligence."
The Home Office said the legal framework governing protests is under constant review and more work needed to be done to make protest organisers accountable under civil, as well as criminal, law.