Senior deputy general secretary, Sue Ferns, argued that while legal changes were important, they were not the silver bullet for reviving union membership.

One of the key changes needed was to give unions access to workplaces. She pointed to Prospect’s proposal for a new ‘Duty to Bargain’ on companies with more than 250 employees.

This would unlock around half of the private sector for trade unions – a policy which has now been adopted by the TUC.

But this on its own would not be enough to drastically increase union membership.

Unions themselves need to change – both by adapting their organising approach and looking at new sectors, she said.

Prospect has been doing this in areas as diverse as renewables and video gaming – and by changing the way it is perceived, especially among young workers.

Laura Pidcock, MP, who leads on this policy area for the Labour party, set out her vision for a new Ministry of Labour and an industrial relations act that would increase access rights and roll out sectoral bargaining across the economy.

However she said that sectoral bargaining must always be a baseline and that it would not replace the workplace organising that is central to trade union membership.

Liv Bailey, deputy general secretary of the Fabian Society, took the audience through the results of focus group work they had conducted with non-unionised workers.

She agreed with Sue that trade unions had a huge image problem, especially with younger people, and that the movement needed to modernise if it was to stay relevant to the changing world of work and people’s aspirations.