Republican Rep. Thaddeus McCotter resigned Friday after failing to gather enough valid signatures to retake his own House seat.

The five-term Michigan congressman said his priorities would now be helping the state attorney general's office investigate the faulty petition filings and finding another job.

He dropped his bid for re-election last month after learning his staff hadn't filed enough valid petition signatures to get him on the Aug. 7 primary ballot. Twice as many signatures as required were turned in, but 80 percent were found to be fake or duplicates. 

McCotter, who briefly mounted an unsuccessful campaign for president last year, also said he didn't have another job lined up but was "unwilling and ill-suited" to be a lobbyist.

"Acutely aware one cannot rebuild their hearth of home amongst the ruins of their U.S. House office, for the sake of my loved ones I must `strike another match, go start anew' by embracing the promotion back from public servant to sovereign citizen," McCotter said in a written statement.