Forest Gate’s Minhaj-ul-Quran welcomed its world leader Dr Muhammad Tahir-ul-Qadri to Westminster.

The Pakistani politician, who issued a fatwa (religious ruling) against terrorism in 2010, was visiting Westminster’s Central Hall to launch an anti-Isis curriculum.

It included educational books written in Arabic, Urdu and English he hopes teachers will use to prevent radicalisation in the classroom.

Speaking to the crowd on June 23, which included Tory peer and former cabinet member Baroness Sayeeda Warsi, he stressed the need to save humanity by fighting terror with peace.

“The time has come when human kind and generations have to arm themselves with ideas of justice,” he said. “People, communities and nations thrive where there is mutual respect, human dignity, tolerance, human values and integration.”

And he advised vigilance against non-violent extremism was necessary to stop it growing into acts of terror.

“The greatest challenge for mankind is that of extremism and terrorism,” he said. “If it’s non-violent extremism today – it will be violent tomorrow. We have to stand up and we have to become vocal. We have to be loyal to the cause – and that cause is peace. Whatever cost I have to pay and we have to pay, we will stand up for peace.”

Dr Qadri said that atrocities committed by Isis, which include drownings, tying explosives around prisoners’ necks and burying Yazidis alive, were not the fault of religion but the fault of the militants’ mindset.

“No faith on Earth justifies it,” he said. “Isis aims at cutting the neck of mankind. Not for the sake of faith – but for the sake of expansion.”

And he criticised those leaving Western democracies that offer education to fight for Isis in Iraq and Syria, saying that they would be punished when they die.

“They have left everything to kill themselves and kill others – why have they gone crazy?” he said.

“You are going to put yourself in the fire – they [Isis] are inviting people to hell.”