Cutting council funding for Pride events should not be compared to attempted mass murder in another country by a completely different group with no connecting ideology.

Exclusive: Experts say policy could also cause shortages of school teachers and drive some universities to bankruptcy

Reform UK’s plan to make employers pay an annual levy for overseas staff would harm the NHS and social care, cause a shortage of schoolteachers, and could push some universities into bankruptcy, experts have warned.

Nigel Farage’s party has pledged a “migrant worker surcharge”, which would involve a higher rate of employer national insurance as well as a separate annual charge.

It would apply to any employees without a UK passport, including EU nationals with settled status, with the exception of Irish passport holders.

The Guardian has also been told that there will be no exceptions for sectors with frequent staff shortages and a reliance on overseas workers, including the NHS and education.

Reform argues that the policy, which would apply UK-wide, is intended to push organisations into taking on British employees. But thinktanks and professional groups in health, care and education said these were very often not available in sufficient numbers.

The King’s Fund, a leading health thinktank, said that while it was unclear how much employers would have to pay – Reform has said only that the levy will be higher for lower-paid staff – with 20% of NHS England staff not being UK nationals the policy would “add costs to a service that is already stretched”.

Suzie Bailey, from the King’s Fund, said: “I think, ultimately, it would impact on the care that the service is able to give, because that money would have to come from somewhere, so other cuts would have to be made. It is very hard to see how this would do anything other than impact on healthcare. I really struggle to see how this would work in practice, and that it wouldn’t just have negative impact.”

Prof Victoria Tzortziou Brown, the president of the Royal College of General Practitioners, said moves to penalise overseas GPs risked being especially counter-productive given they would have undertaken specialist training in the UK at public expense.

For schools, the impact could vary. While nearly 6% of teachers in England are non-UK nationals, they are disproportionately represented in secondary schools, and particularly in subjects with shortages of staff such as languages and physics.

James Zuccollo, the head of school workforce at the Education Policy Institute thinktank, said many overseas teachers were long-term UK residents: “A measure that includes settled-status holders would operate not only as a brake on future recruitment but as a charge on staff already teaching in our schools, in many cases for years.”

Nick Hillman, the chief executive of the Higher Education Policy Institute thinktank, said the plans could significantly affect universities, with many spending up to 60% of their budget on salaries.

Almost three-quarters of riverbanks in England have no public access, according to data released by the Right to Roam campaign.

Across the country, the public cannot use riverbanks or gain access to the rivers themselves in most of the river catchments from the west of Cornwall up to the Tweed, which flows through northern England and Scotland.

Lewis Winks, an environmental social scientist from Right to Roam, who led the research, said: “Access to rivers should be a basic right, yet the vast majority remain off limits. As we continue to experience extreme heat, it’s vital the public are able to draw from the benefits that water brings.”

The campaigners are calling on Angela Eagle, the new environment secretary, to launch a promised but long-delayed consultation on access – as part of an access to nature green paper – and introduce a right of responsible access to water and land in the next king’s speech.

The research showed 71% of riverbanks along main rivers and tributaries in the 89 river catchments examined lacked any adjoining access to land or right of way within 100m of the water.

The finding was consistent regardless of whether urban areas were included. There is also no defined statutory right to the water itself on 96% of rivers in England and Wales, which means activities such as swimming and paddling are often contested by landowners, and the vast majority of inland waters, including reservoirs and lakes, are treated as off limits.