Senate GOP Leader Dean Skelos on Thursday said he was fully behind Republican Rob Astorino’s gubernatorial candidacy and pledged to help elect him.

Skelos spoke on the second day of the Republican convention in Westchester County this morning, the same day the GOP designated Astorino its preferred candidate to take on Gov. Andrew Cuomo this fall.

Skelos, a Long Island Republican who formed a majority coalition with the Independent Democratic Conference last year, has worked well with Democratic Gov. Andrew Cuomo.

With the Senate GOP, Cuomo has gained key legislative victories on same-sex marriage, gun control and a package of tax cuts as well as approving budgets four years in a row before the April 1 deadline.

But Skelos sought to remove any doubt that he wouldn’t help the GOP standard bearer defeat Cuomo.

“It’s a solid party behind him right now,” Skelos said.

“I’m a full-throated Republican so I support Rob Astorino — always have been,” he added.

Cuomo, too, has worked well with Skelos’ home county executive, Nassau’s Ed Mangano, an area that was once a reliable region for GOP turnout.

Skelos insisted there will be help for Astorino, who is also from a suburban county and will likely need to compete with Cuomo for votes there.

“We’re going to work hard for Rob Astorino in Nassau County,” Skelos said.

Skelos predicted Republicans will be able to pick up three to four seats this November, if not an outright majority.

Asked if that would mean an end to the coalition with the IDC, Skelos said it wouldn’t.

“I want to keep that intact,” he said. “I think it’s worked well, we have some differences of opinion, but that’s good. The end result is getting results and I think that’s worked very well.”