Pointing out that most TUC-affiliated unions were politically independent, he said that widespread prosperity was vital to supporting decent public services and that there should be no inherent conflict between the pursuit of growth, and the protection of jobs and workers’ rights.

However, he told the packed fringe event – organised by think-tank Respublica – that without a renaissance in collective bargaining the country wouldn’t overcome the key challenges it faced: low productivity growth, wage stagnation and skills shortages. A collective, independent workplace voice was also needed to ensure that Brexit did not weaken workers' rights.

“Drawing on the diverse workplace experience of unions like Prospect, an opportunity exists to improve productivity, drive economic growth and enhance skills,” Clancy said.

“We know from our own membership polling that at least a quarter of our members voted Conservative at the last election. We also know they have a broad range of views on the big issues of the day such as Brexit.

“It might not chime with common perceptions but most unions, like Prospect, are independent of any political party and purely focus on promoting the interests of members.

“For Prospect, that means being evidence-led and prepared to talk to a range of employers and political parties – even if we don’t always agree.

“It is particularly important to have a constructive dialogue with the government of the day. It may be stating the obvious but the Conservatives are the ones driving the agenda at the moment and we want to be able to influence that positively.

“But this government faces a choice. What sort of workplaces does it want its policies to produce and what say will they give working people and their unions?’

“When doing their job well, unions should be providing a positive challenge to government: holding it to its key pledges on the economy and public serves. Whatever our differing political persuasions, we all want to see the economy and working people thrive.”