Gov. LePage said Tuesday he will veto a bill moving through the Legislature that would allow doctors to help terminally ill patients hasten their deaths.

LePage’s promised veto casts significant doubt on the prospects for the proposal, which is similar to one narrowly defeated in 2015. Two-thirds of the Legislature would have to vote to override a veto.

The bill is similar to a law passed in Vermont in 2013 and to proposals being debated in other states. It says patients who are ill and deemed by their doctors to be within six months of dying could request medication to hasten their deaths, and that physicians could legally prescribe life-ending medications in such cases.

“I’m against it,” he said Monday during a radio interview on WVOM’s “George Hale and Ric Tyler Show.” Asked if the bill is destined for a veto, LePage said, “Yes. Here we are talking about death with dignity and we’re sitting there, human beings, passing judgment on who can live and who can die. No, I don’t believe in it.”

LePage had not declared his position on the proposal when a public hearing at the State House drew dozens of supporters and opponents earlier this month. At the time, his office declined to discuss the bill.

Residents and lawmakers who support the bill offered heart-wrenching stories at the hearing about loved ones who had died and had to suffer, and some read letters from dying Mainers who want the right to choose a peaceful death. Opponents argued the measure is a “slippery slope” that would lead to state-sponsored euthanasia as a means of saving on medical costs for treating the terminally ill.

The primary bill, “An Act to Support Death with Dignity,” is scheduled to be discussed by the members of the Health and Human Services Committee Wednesday. A second aid-in-dying bill, “An Act to Promote Life with Dignity,” also will be discussed Wednesday. The two bills are similar and will likely be combined before the committee votes to send its recommendation to the full Legislature.

The outlook for passage has been uncertain. A similar proposal failed in 2015 by a single vote in the Maine Senate.

However, LePage’s promise of a veto means the proposal now needs the support of two-thirds of the House and Senate, and it would require Republican supporters who vote for the bill to also vote to override a LePage veto.

If the Legislature passes the bill and overrides a veto, Maine would become the sixth state to allow physicians to assist in hastening the death of a terminally ill patient.