An audience of around 100 gave Mr Jamal’s remarks an enthusiastic response during the meeting at Hamilton House, Kings Cross on Thursday.
Mr Jamal spoke alongside StWC convenor Lindsey German, CND General Secretary Kate Hudson and the Muslim Association of Britain (MAB) President Raghad Altikriti.
The meeting was due to be addressed by Shadow Home Secretary Diane Abbott – but she pulled out at the last minute.
Mr Jamal reacted furiously to the PSC being branded one of the “left-wing and associated single issue groups” in an internal anti-extremism guide for counter-terrorism police.
He said this represented “the latest manifestation of the Prevent strategy in action.”
With a CND flag and a Palestinian flag draped at the front of the room, the speakers tried to argue that the right to protest in support of the Palestinian people was under threat by the government’s Prevent programme.
In her speech Ms Altikriti, claimed school children had been referred to Prevent for displaying the Palestinian flag “for those who support the cause of Palestine”.
She claimed Prevent policies, introduced by the government since 2015, had shut down debate on “controversial issues, that carry sometimes extreme views.”
Ms Altikriti added: “There is no proof that having extreme views does lead to violence.”
CND leader Ms Hudson said Jeremy Corbyn had been the subject of a smear campaign similar to what the peace movement had faced, particularly when Michael Foot, one of its key supporters, led Labour in the early 1980s.
“It reminded me of Tory tactics in the general election against the leader of the Labour Party, who was also against nuclear weapons, Jeremy Corbyn, also a supporter of the Stop The War Coalition and a great activist in support of the rights of the Palestinian people," she said.
"So the political attempts used then in the 1980s to destroy the Labour Party's progressive policies .. they use again to undermine to vision of Jeremy Corbyn as a progressive Labour Party leader.”
Ms German, a long-time ally of Mr Corbyn, told the meeting: "When you say you are standing up against racism, when you say you are standing up for the Palestinians … when you say you are stand up on any of these issues, you are regarded as a criminal.”
She said the “Prevent agenda” was being used against those who "speak the truth about Palestine” on university campuses.
She said this had been “aimed historically against the Muslim community” in the UK, with demonstrations against Israel’s actions in Gaza “criminalised”.
Ms German said Muslim’s were “being branded as extremists or terrorists”. She added: "We said in 2003 that if this war on terror goes on we will have more terrorism.
“That’s what they have done. And now they are trying to blame it on the people who told them in the first place this would be a disaterous course of action.”
Speaking later, Ms Altikriti said “you have to listen to young people” who complain “the government’s policy home and foreign” causes their anger.
