The Lib Dems have called for the police to show more restraint
The Lib Dems have attacked police handling of recent high-profile public demonstrations, expressing concerns about their tactics and use of force.
Party members criticised the practice of "kettling" and the use of baton charges during the G20 protests in London in April.
One MP who was present at the protest said the police had "broken a cardinal rule by using aggression first".
Members backed calls for all uniformed officers to wear ID or be disciplined.
Shadow justice spokesman David Howarth said something had gone "seriously wrong" in the policing of the G20 demonstration and other high-profile events such as 2008 demonstration outside the Kingsnorth power station.
While more recent climate change protests had been handled more sensitively, Mr Howarth said the police had to stop treating all protesters as potential criminals if the fundamental democratic right to protest was to be protected.
Members approved a motion calling for the police to use "aggressive and intimidatory" tactics only when necessary and an end to the pre-emptive arrest of protesters and seizure of personal property during demonstrations.