Veteran campaigner Harry Leslie Smith, 92, won a standing ovation as he spoke about his life in the 1920s and ’30s, the poverty and destitution, and the determination after 1945 to create a fairer Britain, the welfare state, National Health Service, decent housing and wages.

He accused the government of promoting fear of terrorism, immigrants and trade unions.

“They have treated the poor and the vulnerable with disdain, and are trying to break the will of the unions to create a more just and equal society.

“Sadly my generation’s greatest achievement, the welfare state, has been tarnished by austerity through the power of right-wing demagogues,” he said.

“I warn you that my past could become your future.”