Former Massachusetts Gov. Mitt Romney, the 2012 Republican presidential candidate and potential 2016 contender, rips Gov. Cuomo as “a typical corrupt New York politician’’ in a tough fund-raising letter being sent Monday by Rob Astorino’s campaign for governor.

The letter, a copy of which was obtained by The Post, accuses Cuomo of wasting millions of taxpayer dollars “to fund his ludicrous Start-Up New York campaign,’’ which, Romney contends, has done virtually nothing to improve the state’s business climate.

“The unfortunate truth is New York has the highest taxes in America. The state has the worst economic outlook in the country, and since Gov. Cuomo took office, 400,000 people have relocated to states offering more opportunity,’’ says the letter.

Romney also seeks to make the case for Astorino’s electoral appeal by noting, “He was twice elected [executive] in Democratic Westchester County because he effectively governs in a bipartisan way.”

The letter is being sent by regular mail and e-mail to more than 50,000 Romney and GOP contributors in hopes of boosting Astorino’s financially hard-pressed campaign.

Astorino spokesman William O’Reilly said Romney’s linkage of Cuomo to corruption referred to the governor’s involvement in the ongoing Moreland Act Commission scandal, his “protection of [Assembly Speaker Sheldon] Silver in the face of sexual-harassment coverup charges,’’ and his spending of public monies on a TV campaign designed to boost his re-election chances.

O’Reilly said Romney may attend a “pre-Election Day’’ event with Astorino in New York.

Earlier this month, former Florida Gov. Jeb Bush, another potential presidential contender, penned a fund-raising letter for Astorino, but it steered clear of a direct attack on Cuomo.

The Romney and Bush letters are being seen in GOP circles as indirect shots at the presidential aspirations of New Jersey Gov. Chris Christie, who, despite being chairman of the Republican Governors Association, has appeared to be a Cuomo ally by refusing to help raise funds for Astorino.

“At this point, we’ve marked Christie off as a lost cause,’’ O’Reilly said.

Cuomo has made it clear that his goal for reelection is to at least equal the landslide, 64 percent victory margin won by his father, Mario Cuomo, when he first ran for re-election in 1986.

But a new Quinnipiac poll made public last week showed that a landslide win of that magnitude appears out of Cuomo’s grasp.

While the poll of likely voters found Cuomo with a strong, 20-point lead over Astorino, it also found the governor may end up winning the election with a bare majority of the vote.

The surprising poll showed Cuomo, who has been outspending Astorino by more than 20 to 1, garnering just 51 percent of the total vote.

What’s more, the poll found Cuomo viewed favorably by just 50 percent of all voters and only 43 percent of male voters.

And among men alone, the poll found Cuomo leading Astorino by just 44 percent to 39 percent.

“I believe this race is going to be surprisingly close,’’ said Astorino pollster James McLaughlin.

“This race is many ways reminds me of the Mike Bloomberg/Bill Thompson race, which was much closer than people realized.

“You have almost half of New York voters saying they’re not voting for this guy after he’s spent tens of millions of dollars, and even 20 percent of Democrats in the Quinnipiac poll weren’t supporting him,’’ he continued.

Noted a prominent Democratic strategist, “The governor’s race is going to be a lot tighter than Cuomo thought it would be.’’