As Sen. Roy McDonald continues to mull his campaign’s future, LGBT rights groups are sending him a clear message: We’ve got your back.

McDonald, one of the four Republicans to back the 2011 legalization of same-sex marriage, appears to have all but lost the Republican line this fall to the County Clerk Kathy Marchione.

But gay-rights groups, some of which are pushing for the legalization of same-sex marriages in other states, hope McDonald will stay in the race on the Independence Party line.

“At the end of the day, we’re confident Senator McDonald will stay,” said Lynn Faria, the executive director of the Empire State Pride Agenda, in a phone interview. “Should he stay in the race, we’re behind him.”

And they’re backing it up with promises of both financial help and boots on the ground assistance.

Faria said much of that would materialize to what groups provided during the primary: “mobilizing volunteers, financial contributions, phone banking, providing boots on the ground. I expect we’ll continue with some of those options moving into the general, moving  into November.”

ESPA did max out its donations to McDonald after he, along with Sens. Stephen Saland, Mark Grisanti and James Alesi voted in the favor of the measure following a period of intense lobbying from a pro-gay marriage umbrella group, New Yorkers United For Marriage, and from Gov. Andrew Cuomo.

But there is a deep well of wealthy, pro-gay marriage donors that McDonald can tap in to, should he continue his race. The group New York Unity PAC, an effort fueled in part by Republican activists who back same-sex marriage legalization, reported spending more than $210,000 on ads, direct mail and robocalls, in its recent 10-day post primary filing.

McDonald already had received maximum contributions from a variety of gay marriage supporters, making the Republican primary one of the most expensive in the state’s history.

Meanwhile, a poll of the district is expected to be released later this week that will shine a light on McDonald’s potential path to victory in a three-way race that includes Marchione and Democrat Robin Andrews, who is openly gay.

Andrews presence in the race has given Democrats new hope that should McDonald see it through November, a split, Republican and conservative electorate could actually give them a chance at grabbing the seat.

“The pride agenda has a long history of bipartisan support and standing by those individuals who support our community,” Faria said.

Cuomo said earlier today he is “concerned” about McDonald’s race and has said he hopes both Saland and McDonald are re-elected.

But he’s stopped at a full-throated, official endorsement of the Republicans running for re-election. Cuomo, who has a 70 percent approval rating, said last week he probably would have helped more than hurt the GOP candidates in a primary, but has not ruled out endorsing Republicans later this fall.

Marchione, meanwhile, will most certainly be supported by the Senate Republican Campaign Committee, which has $3.5 million in cash on hand.

Time is of the essence for gay-rights advocates to keep McDonald from dropping out. His campaign released a statement saying McDonald would determine the future of his campaign later this week or early next week.