TUC general secretary Paul Nowak said on Monday that the union federation will train at least 500 new black activists every year for reps to better reflect today’s working class.

In his first speech at Congress after becoming chief last December, he received a standing ovation as he set out plans to grow union membership.

He said: “By any measure it’s been a massive year for unions, but despite the wins, despite the media coverage, despite the new activists, our membership is not growing.

“So many young workers support our campaigns, but they don’t join our unions.

“Reps are the beating heart of our movement, but our reps need to reflect today’s working class — so, starting today, the TUC will train at least 500 new black activists each and every year.”

He also drew on his roots as he blasted the Tories’ anti-immigrant rhetoric and Illegal Immigration Act.

Mr Nowak, whose grandfathers came from Hong Kong and Poland, said: “For me it is personal because the real enemies of the working class in this country don’t arrive in a small boat, they fly in by private jet.

“Every migrant is my sister, my brother, and this government shames us all, because our country should never turn its back, never turn its back on those fleeing persecution, poverty or war.”

He said the Tories have “broken Britain,” saying: “They’ve had 13 years to sort out crumbling concrete in our schools but five days before the new term, they tell schools they can’t open.

“Because — and I quote the Education Secretary — everyone sat on their arses. Could you think of a more perfect metaphor for this government?”

He vowed strikes would be called if the government’s Minimum Services Levels Act is used to sack a worker for taking part in industrial action.