AUGUSTA — Maine residents in need of psychiatric care are being hurt by a shortage of beds as legislators deadlock on a proposal to free up space by building a new facility, according to a leading mental health advocate in the state.

Legislative leaders last week did not approve construction of the proposed facility – which could be built in Augusta and cost $3 million to $5 million – after Democrats raised concerns about who would have oversight of the facility and how it would be funded in the future.

The leaders divided along party lines, and Republican Gov. Paul LePage says his administration will avoid Democrats’ jurisdiction by building the 21-bed facility outside of the Capitol area in Augusta.

A long-overlooked law says that a group of legislative leaders must approve buildings built in a special zone in Augusta known as the Capitol area. The plan has received local and state administrative approval.

Jenna Mehnert, executive director of the Maine chapter of the National Alliance on Mental Illness, said she emailed the leaders a week ago and urged them to support building the unit. Democrat Rep. Sara Gideon, who is nominated as Maine’s next House speaker, said legislators want to protect people with serious mental illness.

The Department of Health and Human Services “has never brought this proposal to the Legislature, but is essentially threatening to build the project elsewhere and at greater cost if they don’t get their way,” she said in a statement.

But Mehnert said Maine faces a “crisis,” with increasing numbers of individuals waiting in emergency rooms for beds at the state’s only psychiatric center, Riverview Psychiatric Facility.

Mehnert said her group is getting many calls about people spending between eight and 12 days in the halls of emergency rooms because of a lack of space. She said the goal is to get people who need hospitalization into beds in 48 hours and not have them waiting for weeks.

The proposed facility would house individuals who receive hospital care after courts deem them not criminally responsible for a wrongdoing because of their mental state.

Mehnert said she hopes Maine will also add state psychiatric beds for minors in the future.

The LePage administration says the proposed facility would be operated by a private vendor and would help the psychiatric center regain federal certification it lost in 2013 following concerns about staffing and the use of Tasers on patients.

In an email, a DHHS spokeswoman said the facility would help Riverview “meet the statewide demand for inpatient psychiatric capacity for civil patients.”