They say visits have risen by 25 per cent in five years whilst council funding has been cut, leaving a shortfall in resources.
In 2016 there were 2,456,779 new attendances at sexual health clinics, compared with 1,941,801 in 2012.
The previous Government cut councils’ public health grant by £331 million from 2016 to 2021, following a £200 million in-year reduction in 2015-16.
In 2016, there were 417,600 new STI diagnoses made at sexual health services across England.
Of these, the most commonly diagnosed STIs were chlamydia - almost half of all diagnoses - first episode genital warts and gonorrhoea.
The Local Government Association (LGA), which represents more than 370 councils in England and Wales, says the cuts have left local authorities struggling to keep up with increased demand.
Cllr Izzi Seccombe, Chairman of the LGA’s Community Wellbeing Board, said: “While it is encouraging that more and more people are taking their own and their partners’ sexual health seriously, we are concerned that this increase in demand is creating capacity and resource issues for councils.
“We are concerned that this will see waiting times start to increase and patient experience deteriorate.
“The reduction in public health funding could also compound problems further and impact on councils’ ability to meet demand and respond to unforeseen outbreaks.
“We cannot tackle this by stretching services even thinner.
“It is obviously good news that diagnoses of sexually transmitted infections are down, but sexual health services are now reaching a tipping point where it will be extremely challenging to maintain this progress.
“Once again this is an example of councils inheriting the responsibility of public health when it was transferred from the NHS in 2013, but without the necessary resources to deliver services.”
Council leaders say it is good news more people are taking responsibility for their sexual health, but warn this is placing a significant strain on councils’ resources.
And while the number of new diagnoses of sexually transmitted infections fell by four per cent last year, councils are warning that it will be “extremely challenging” to maintain services at the current level.