Former Rep. Michael Grimm will officially announce his campaign to get his old job back Oct. 1. View Full Caption DNAinfo/Nicholas Rizzi

STATEN ISLAND — Former Rep. Michael Grimm, who spent nearly seven months in prison on tax fraud charges and has lost the faith of all other Staten Island elected Republican officials, next year will run to get his old seat back, according to a Republican insider and NY1.

Grimm plans to officially announce his campaign Oct. 1 to take on Rep. Dan Donovan in a Republican primary for his old job representing Staten Island and parts of Brooklyn, NY1 first reported.

While Grimm remains popular with some voters in the borough, he won't get help from New York's entire elected Republican party who last month came out against his potential run and said they were "extremely disappointed" he was even considering it.

So far, Grimm has been trying to ride the borough's pro-Trump wave into office by writing op-eds defending the president and slamming Donovan for not supporting him or voting Republican enough in Congress.

"We're not really concerned about a challenge from a felon who was one of the most liberal members of Congress," said Jessica Proud, spokeswoman for Donovan's re-election campaign, in a statement. "Voters won't be duped by him again."

Donovan, the city's lone Republican congressman, supported Trump in the primary and called him a personal friend. Despite voting against the GOP health care bill, he has voted 88.9 percent in line with the president on other issues, according to FiveThirtyEight.

Grimm's mentor and main backer, Republican powerbroker Guy Molinari, also previously called on the borough's elected officials to publicly condemn Trump during his primary run, the Staten Island Advance reported.

If he does takedown Donovan in the primary, he still has to face off against a Democratic candidate for the seat and it's unlikely he'll receive monetary support from Washington's GOP for that race, the insider told DNAinfo New York.

The borough's Democratic party — which actually has 47,954 more registered voters than Staten Island Republicans — has had a resurgence sparked by anger over President Trump and currently have five candidates vying for the chance to run for the seat.

Grimm was first elected to Congress in 2010 when he defeated then-incumbent Michael McMahon in an election.

However, he had numerous scandals during his tenure, including threatening to throw a NY1 reporter off a balcony after he asked a question about probes into his fundraising.

Grimm was later indicted on tax fraud charges after he underreported more than $1 million in profits from an Upper East Side eatery he co-owned before he took office.

He held onto his seat while under indictment in 2014 against a better funded Democratic candidate but pleaded guilty to tax fraud and resigned from his seat shortly after his win. Donovan won a May 2015 special election to replace Grimm.

Grimm did not immediately respond to a request for comment.