Independent negotiators should settle disputes between police and protesters to stop a repeat of the violence at the G20 summit where thousands of demonstrators were contained for hours using the controversial tactic of kettling, a parliamentary inquiry proposes today.

The report, by the joint committee on human rights, says police and demonstrators were to blame for failure to communicate in advance of the protests in the City of London in April.

It calls on the government to consider introducing a system of independent mediation – modelled on Acas, the body which settles industrial disputes – to improve dialogue in the run-up to protests.

The Met’s handling of the G20 protests has been under sustained criticism since the death of Ian Tomlinson, the 47-year-old newspaper vendor, who collapsed after being attacked by an officer who was not wearing his badge number. The committee said it noted “with concern” that the Independent Police Complaints Commission, which is still investigating Tomlinson’s death, has received 277 additional complaints about the Met’s operation.

The report said trust in the police could be “seriously damaged” if officers were not held to account. Wearing of police badge numbers was “crucial to ensuring that the police are accountable for their actions”, and should be made a legal requirement, it said.

In recent weeks, the Met has been criticised by HM Inspectorate of Constabulary, the official police watchdog, which said in its interim findings that there should be a national overhaul of the public order guidance given to police forces, and the home affairs select committee, which suggested the G20 protests exposed how officers had not received sufficient training.

All three inquiries have found serious failings in the Met’s containment of protesters using the tactic known as kettling, near the Bank of England. They also noted that the technique had been recently ruled lawful by the law lords in some circumstances. That decision is being appealed against at the European court of human rights.

Keith Vaz MP, chairman of the home affairs committee, will today come out against the use of kettling for the first time, saying it is “a very worrying tactic” that is potentially dangerous and should be abandoned.

“I personally am against it because I think the containment of people in those circumstances will lead to situations where either the public, somebody who is ill wants to come out of the kettle, or members of the press who have I think a right to be wherever they want to be in a protest of this kind, can’t come out,” he says in today’s episode of BBC Radio 4′s The Long View. Asked by the presenter, Jonathan Freedland, if he wanted to see the back of it, Vaz replies: “I would”.

Today’s report refers to evidence from Tom Brake MP, who attended the protest as a legal observer and witnessed police refusing to give permission to leave to a man who needed to care for his 83-year-old mother and a diabetic who needed to get insulin. The committee said facilities such as food and water were not available to protesters who, when leaving the kettle, were searched and asked for their details. While kettling could be “useful and lawful in some circumstances”, the implementation of the tactic at the G20 “did not give sufficient weight” to the human rights of individuals being contained, it said.

Andrew Dismore MP, the committee’s chairman, said: “I think police just saw this protest as trouble, not a demonstration that they had a legal obligation to try and facilitate. “There were obvious problems with this policing operation. While kettling may be a helpful tactic, it can trap peaceful protesters for hours.”

He added there was “huge mistrust” between police and protesters in the days leading up to the demonstration, and an independent broker could in the future help resolve disputes.

The report also said the media and not police were at fault for “talking up the prospect of violence and severe dirsuption” ahead of the protests, and called for the Met to release its report into the death of Blair Peach, who is widely believed to have been killed by Met officer at a demonstration in 1979.

The Met and the Association of Chief Police Officers said they were reviewing their approach to policing protests and would take note of the report.