TUC general secretary Paul Nowak suggested a “Cabinet full of millionaires” might not fully understand the squeeze on living standards faced by ordinary workers.

As up to 500,000 workers took part in the biggest strike in a decade, Mr Nowak said: “This is not going to go away.”

Members of seven trade unions took industrial action yesterday, affecting schools, universities, trains and buses.

Speaking in Westminster, he said: “There isn’t a single public sector worker who is taking industrial action today that wants to be on strike.

“They are losing pay, they are not being able to deliver the services they are proud to deliver to the public.

“But the responsibility for these strikes lies firmly with the Government. It’s been months now and still the Government hasn’t sat down and seriously talked about a real pay rise for our public sector workers.

“It really is now the responsibility of Rishi Sunak and Jeremy Hunt to get round the table and make sure the resources are available to fund decent pay in our public services.”

Asked what Mr Sunak is doing to sort out the industrial action, his official spokesman said: “We want to have further talks with the unions. Some of those discussions have been constructive.

“We have to balance that against the need to be fair to all taxpayers, the majority of whom don’t work for the public sector.”

Parents joined striking teachers in demonstrations across the country as many schools closed their doors to pupils.

Thousands of teachers gathered outside Broadcasting House on Wednesday as they prepared to march to Westminster.

Teachers in England and Wales, who are members of the National Education Union (NEU), took part in the first national strike since 2016, which threatened disruption to more than 23,000 schools.

Thousands of students have joined striking university staff on picket lines across the country, the University and College Union (UCU) has said.

Universities across the UK have been hit by walkouts, with lectures and seminars cancelled, as 70,000 staff have begun an unprecedented period of strike action over pay, working conditions and pensions.

The UCU expects 2.5 million students to be affected by 18 days of strikes during February and March.

A number of Labour MPs have joined picket lines to support striking workers, despite party leader Keir Starmer previously saying no MP should be on a picket line “if they want to be in government”.

Left-winger Sam Tarry, the former frontbencher who represents Islington South, was previously sacked as a shadow transport minister after giving interviews from a picket line in July last year.

He defended his decision to join striking teachers in his constituency against criticism by the Conservative Party, saying: “Much rather you focused on fairer pay for front line workers than me standing on picket lines… as Labour MPs have done so for over a 100 years.”

Former shadow chancellor John McDonnell told the PA news agency he believed Labour MPs should be on the picket lines, as he joined striking workers outside the Treasury and various locations in his constituency of Hayes and Harlington.

It comes as Network Rail (NR) made a “newly revised” offer to the biggest rail workers’ union in a bid to break the deadlock over a long-running dispute about pay, jobs and conditions.

The union said its executive will consider the details of the offer.

Sunak warned to expect to more strikes as half a million take to the streets