Republicans are so nervous about Staten Island Rep. Michael Grimm’s re-election chances that they’ve quietly reached out to former GOP Congressman Vito Fossella — who quit five years ago after confessing to having a secret second family — to make a comeback for his old seat, The Post has learned.

Grimm is currently the subject of an ongoing Justice Department probe that centers on whether his campaign solicited illegal donations from foreigners during his 2010 campaign.

Grimm, an ex-Marine and FBI agent, denies any wrongdoing.

Fossella, 48, told The Post that he has been contacted by local and national Republicans — including former congressional colleagues and other D.C. power brokers — to sound out his interest in returning to Congress.

“There are significant people who have approached me to run,” Fossella said. “They say I did a good job and should enter the public arena again.

“The number of inquiries have increased in the past few months.”

Fossella, who is married to childhood sweetheart Mary Pat and has three children, was engulfed in scandal after a DWI arrest in the D.C. area in May 2008.

He then confessed to having a secret second life, fathering a child in an extramarital affair with a retired Air Force lieutentant colonel.

Fossella did not seek re-election that year.

Now a managing director at Al D’Amato’s lobbying firm, Park Strategies, Fossella has since reconciled with his first family.

He remains popular with voters in the Staten Island-south Brooklyn district he represented from 1997 to 2008.

Fossella was also warmly embraced by New York GOP delegates during the National Republican Party Convention in Tampa, Fla. in 2012

The ex-pol said he was “flattered” by the support and still considers public service a “noble calling.”

But Fossella said he likes his current job and life and flatly insisted he has no intention of returning to the political ring.

“I told people I have no plans to seek office at this point in my life,” he said.

After relinquishing his seat, Fossella was succeeded by Democrat Michael McMahon, who defeated a weak GOP candidate.

But Grimm topped McMahon in 2010 amid a Tea Party furor over ObamaCare. Grimm narrowly won re-election last year.

A former Grimm fund-raiser, Israeli national Ofer Biton, pleaded guilty in August to visa fraud. Investigators are trying to determine whether Grimm offered to help Biton, an Israeli citizen, obtain a green card.

Biton has close ties to Israeli Rabbi Yoshiiyahu Yosef Pinto, whose devoted followers donated tens of thousands of dollars to Grimm’s 2010 campaign.

Democratic Brooklyn Councilman Domenic Recchia is laying the groundwork to challenge Grimm next year.

National Republican Congressional Committee spokesman Ian Prior the GOP is totally committed to Grimm’s re-election.

Prior said Grimm is part of the NRCC’s “Patriot Program”, meaning it is targeting his race for additional resources.

The NRCC, he also noted, just posted a new website that specifically attacks Grimm’s likely Democratic opponent, Domenic Recchia.

Grimm said Wednesday night, “As an independent voice for Staten Island and Brooklyn, my job is to fight for what’s best for my district. Sometimes that requires actions that are not in lock-step with the party, but I didn’t run for office to be liked; I ran to get results. Baseless rumors will not keep me from focusing on my work in Congress and fighting for the people I proudly represent.”

Staten Island’s GOP Chair, John Antoniello, balked. “This is clearly a false statement planted by Democrats that lacks any credibility. Michael Grimm is our congressman and our candidate. He’s done a great job and we’re proud to have him as our representative.”

New York State Republican Party Chairman Ed Cox said, “Michael Grimm has the party’s full support and any other rumors are simply false. His record has been exemplary and not only do we stand behind him in his re-election campaign, we expect a big victory.”