Greens leader Nick McKim pledged to invest $300,000 over three years in suicide prevention programs and $910,000 in advocacy services for people with mental health issues.

"Often people with mental health issues find it really hard to protect their own rights, including human rights," Mr McKim said.

"This is about safeguarding the rights of Tasmanians with mental health disorders."

Three new full-time advocates would be employed across the state under the policy, adding to the one currently available.

Mr McKim said there was a long waiting list for mental health advocacy services through Advocacy Tasmania.

An immediate review of all legislation pertaining to people with mental health issues would be enacted.

Mr McKim said the Mental Health Act 1996 - which has been under review for three years - was "out of date" and "an inadequate tool to protect human rights of Tasmanians with mental health disorders".

"We will review the legislation to make sure that not only are we investing more in people with mental health issues but also that the legislative frameworks are there to protect them and their human rights."

In any year, one in five people have a mental illness.

The Mental Health Council of Tasmania on Friday aired concerns that mental health had been left off the election agenda.

Council executive officer Michelle Swallow said all parties had made health and hospital commitments but there had been "an appalling lack of announcements" on what the parties would do to address mental health issues.

Ms Swallow said the Tasmanian Government must make an investment in the promotion, prevention and early intervention of mental illness to ensure that fewer people needed to access emergency and acute services.