Mental health services in England risk being overwhelmed by a combination of rising demand and staff shortages, a survey of NHS trusts suggests.
The poll by NHS Providers, which represents trusts, found seven in 10 mental health leaders expected demand to increase this year.
But fewer than one in three was confident they had enough staff to deliver services.
Ministers said extra money being invested would help improve care.
It comes as an investigation by BBC Radio Five Live found the growing demand for mental health support was being felt in the ambulance service too.
Responses obtained under the Freedom of Information Act showed there was a growing number of ambulance call-outs to people suffering from suspected mental health problems.
In 2015-16, there were nearly 279,000 call-outs, up from 240,000 the previous year, according to the 13 out of 14 UK services that responded.
Louise Rubin, of the charity Mind, said part of the rise was likely to be down to an increasing trend for people with mental health problems who come into contact with the police to be transported by ambulance rather than with them.
She said this was a positive move, but it was “unlikely to be the full picture”.
“We are concerned that people coming forward and seeking help for mental health problems are not getting the support they need early enough, which means they are more likely to become more unwell and reach crisis point.”
‘Gap between ambition and reality’
Saffron Cordery, of NHS Providers, said the biggest growth in demand was being seen in children’s mental health services.
The survey carried out by her organisation received responses from 43 chairs and chief executives from 37 trusts, nearly two-thirds of the total number of mental health trusts in England.
She said the findings were concerning.
“These concerns point to a growing gap between the government’s welcome ambition for the care of people with mental health needs and the reality of services they are receiving on the front line.”
A Department of Health spokeswoman said: “We’re committed to seeing mental health services improve on the ground.”
She said by 2021 services would be getting an extra £1bn a year. Last year they were given £11.6bn.
She said that would help improve crisis resolution, home treatment teams and mental health support in A&E in particular.