ALBANY — Former US Sen. Alfonse D’Amato yesterday called Newt Gingrich “a slick salesman with no chance of winning the general election,’’ and vowed not to support him if he wins the GOP nomination.

D’Amato, who worked with the former House speaker during his 18 years in the Senate, contended Gingrich’s “controversial past history, both in government and in his personal life,’’ made him unelectable.

“I think he does have a chance of winning the nomination but no chance of winning the general election,’’ D’Amato told The Post.

“The Democrats will drag out his past history in government, and in his personal life, and in his business relationships, and that will prevent him from being elected,’’ continued D’Amato, referring to Gingrich’s controversial role as speaker, his three marriages, and his just-revealed receipt of $1.8 million in fees from Freddie Mac, the near-bankrupt government-controlled mortgage company blamed in part for the nation’s housing crisis.