A charity is filing legal action against NHS England after it refused to commission HIV-preventing drugs.

Pre-Exposure Prophylaxis (PrEP) drug Truvada can reduce people’s chances of being infected with HIV by up to 99 percent, if taken daily.

Though the drug is endorsed by the World Health Organisation and is available to at-risk gay men in a number of countries, NHS England has repeatedly deferred a decision on the drugs – despite a pilot scheme showed the drugs were incredibly effective at reducing HIV transmission among men who have sex with men (MSM).

This week, NHS England ruled out a large scale roll-out for PrEP instead funding a further two-year trial at “early implementer” sites.

Sexual health groups say the decision puts men at risk, while London Councils accused the NHS of “playing a waiting game”, stringing out a decision until drug patents expire.

The National AIDS Trust has now confirmed it will be seeking legal action against NHS England, calling on people to help fund their efforts.

In a letter to NHS England made public on its website, NAT says it will be seeking a judicial view due to body’s “illogical sudden change of position”.

The filing questions why NHS England had consulted on making PrEP available, given it now retroactively claims it has no legal authority to do so.

Noting that NHS England is still funding the early implementer sites while claiming not to have legal authority on the issue, the letter adds: “It is unclear why it is permissible to fund the pilot and not the PrEP proposal that had been worked up.”

“NAT’s intention remains to resolve this matter outside litigation with the Defendant if at all possible… it remains our client’s intention to continue the ongoing discussions with the Defendant alongside serving this formal correspondence and it is hoped that the issue of proceedings will be unnecessary.”

A call for donations added: “NHS England is sitting on something that could be the beginning of the end for HIV – PrEP – but it can only work if they make it available.

“With 17 people a day diagnosed with HIV in the UK we need PrEP now.

“However, NHS England have decided they aren’t responsible for paying for it. We disagree. That’s why we’ve started a campaign and are planning legal action.”

The NAT added: “We’re in the process of lodging a judicial review in the High Court – to challenge NHS England’s decision. But there are risks attached, including court costs.

“NAT is a small charity and we can’t cover the campaign and legal costs by ourselves. We’re confident in the strength of our case, but we can’t be sure what the outcome will be.

“We’ll be asking the judge and NHS England to keep legal costs to a minimum but we still need public support to make this possible and cover our campaign expenses.”

NAT is aiming to raise £10,000 towards action on the issue.

NHS England insists the decision to commission PrEP would lie with local authorities – but after cuts to local government spending, most remaining local HIV prevention budgets are under threat or stretched to their limit.