Five trade union general secretaries have written a joint letter to The Guardian condemning government proposals that will deny access to justice for workers suffering injuries that could include a collapsed lung, a fractured wrist or elbow and loss of front teeth.

The 16 November letter, written ahead of the Civil Liability Bill completing its passage through parliament on 20 November, states: “The government say that the bill will tackle a whiplash ‘epidemic’, but it hides a £1.3bn annual gift to the insurers, a loss to government coffers of £146m a year, and an assault on access to justice that will impact hundreds of thousands of people whose claims have nothing to do with whiplash.”

It adds: “By statutory instrument, the government plans to sneak through a doubling of the small claims limit, below which injured people don’t get their legal fees paid. Up to 40 per cent of those injured at work will lose their rights. Thousands of workers will be left fighting insurers on their own and in their own time. Injured people whose claim has a value of up to £2,000 – thousands of people a year – will be expected to take on well-funded insurers on their own.”

The letter concludes: “The government’s proposed changes are a green light to irresponsible employers to cut corners on safety in the knowledge that injured workers will either not seek compensation or struggle to do so on their own. The government is using the furore around whiplash claims as a smokescreen to attack vulnerable claimants and further enrich their friends in the insurance industry (who have already saved £11bn since 2013 due to earlier injury legal reforms). Injured workers should be exempt from any increase, and on behalf of those injured through no fault of their own we intend to oppose these proposals every step of the way.”

The letter is signed by general secretaries Paddy Lillis of Usdaw, Len McCluskey of Unite, Tim Roache of GMB, Dave Prentis of UNISON and Mick Cash of RMT.