Conservative leader David Cameron is being urged to set out his position on mental health services, following its omission from a wide-ranging speech on NHS reform last week.

Charity Rethink has written to Mr Cameron expressing disappointment that his speech covered 16 issues, including infectious diseases and accident and emergency services, but failed to mention mental health.

This is despite it being the biggest single spending area in the NHS, taking up nearly a third of GPs’ time. The letter says: “We were disappointed that in a speech discussing the future of the NHS and how to deliver a standard of quality healthcare that matches patient expectations, mental healthcare was not mentioned once.”

All available evidence suggests the current economic downturn will increase demand on mental health services, the letter says.

One mental health trust chief executive told HSJ he was “greatly worried” that the Conservatives had so far said little about mental health, given their likelihood of winning next year’s general election.

Added to financial uncertainties, trusts felt they were “planning in the dark”, he said.

“We don’t want to be misleading clinicians by saying we’re going to develop services and then have to backtrack,” the chief executive said.

A Conservative Party spokeswoman said Mr Cameron was away due to the parliamentary recess but would respond to the Rethink letter in due course.

Mental Health Network director Steve Shrubb said he had been having “positive discussions” with the Conservatives about a possible TV campaign promoting mental health.

He said: “They have some emerging ideas around public health but at this stage it’s more difficult to get a sense about how they feel about actual services. Clearly I’d have liked them to say more.”

Neither of the two main parties has talked much about mental health, he added.