A move to slash spending on HIV prevention was stopped after it threatened to embarrass the Government ahead of next weekend's Ending HIV Big Gay Out.

Health Minister David Clark confirmed he had directed ministry officials to stop a planned $202,000 cut to the annual budget of the NZ Aids Foundation, after being asked for comment by the Herald on Sunday.

The Aids Foundation planned to use next Sunday's Ending HIV Big Gay Out in Auckland - the event's 20th anniversary - to urge Prime Minister Jacinda Ardern and other political attendees to reverse the funding reduction.

Ardern and politicians including Finance Minister Grant Robertson have been regular attendees at past Big Gay Outs, with Labour highlighting its commitment to helping end HIV transmissions in New Zealand by 2025.

However, the Ministry of Health recently told the NZ Aids Foundation that from July it would lose $202,000 from its annual budget, money that supported the foundation's science and policy team.

The foundation has a critical role in preventing the transmission of HIV and supporting Kiwis living with HIV.

It also works in other areas of sexual health, including efforts to curb a worsening syphilis epidemic that has killed babies after being passed on in pregnancy.

NZ Aids Foundation chief executive Dr Jason Myers said the reduced funding could have meant reduced services such as HIV testing, in order to keep critical science and policy work going.

"[That team] is the engine room for making sure that our programmes and services are evidence based. And it's also the team that monitors and evaluates all our work to make sure that we are getting the job done."

Health Minister David Clark directed the ministry to reconsider the proposed cuts to the NZ Aids Foundation budget. Photo / Mark Mitchell

After being asked for comment, Clark said he had directed the ministry to reconsider, given the Aids Foundation's proven track record.

Clark said the proposed reduction in funding was part of a new sexual and reproductive health action plan, and related to science and policy advice and not health promotion and prevention work.

Grant Pollard, the ministry's group manager for population health, said, as with all contracts, funding is regularly reviewed. The ministry's contract with the foundation is currently $4.23 million a year.

"While there is scope to continue funding NZAF at the present rate, this is subject to further contract discussions about the services to be provided.

"The ministry is committed to continuing its support for NZAF and its Ending HIV campaign, which includes the aspiration goal of ending new HIV transmissions in New Zealand by 2025."