In an open letter to the government, published in The Guardian today and signed by the General Secretaries of the TUC and Unite, the group of signatories emphasise that claims lodged between April and June this year have fallen by 81 per cent compared to the previous year.

It draws on research by the Universities of Bristol and Strathclyde with users of Citizens Advice Bureaux which found no evidence of vexatious claims or widespread abuse of the system – the reason cited by minsters for the introduction of the fees.

The letter follows the news that Unison will appeal the High Court's decision to reject the union’s legal challenge to the fees charged to claimants taking their employer to tribunal - which can be up to £1,200 - on the grounds that the introduction of fees would deny access to justice for workers and had a disproportionate impact on women.