[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2010/images/04/05/art.rnc.gi.jpg caption ="Sean Mahoney resigned from the RNC in protest last month and is launching a bid for Congress in New Hampshire."](CNN) - The former Republican National Committee member who resigned his post in protest after a high-profile spending scandal is embarking on a run for Congress in New Hampshire – and he's attacking his own party in the process.
Though his entry into the race against Democratic Rep. Carol Shea-Porter was expected, Portsmouth businessman Sean Mahoney officially joined the crowded GOP field on Monday with a Web video attacking not just Shea-Porter, but also the Republican Party that he claims "abandoned" him.
Mahoney, who resigned from the RNC earlier this month, is seen in the video giving a speech to Granite State Republicans.
"I'm not here to just cast aspersions on the Democrats," he says in the video, "because quite frankly, I'm a member of the Republican Party. But the Republicans are just as to blame for some of the mess we're in right now. Over the last 10 years, my Republican Party abandoned me as a conservative."
In a letter to RNC Chairman Michael Steele on April 6, Mahoney stepped down as one New Hampshire's three national committee members and blasted the party for demonstrating "a complete lack of respect for RNC donors" by spending money on private planes, car services and "high-priced junkets."
The RNC has succumbed to "the out-of-touch, free-spending culture of Washington," he said in the letter, sent to Steele after it was revealed the committee funded an outing at a sex-themed Hollywood night club.
Three Republicans are already gunning to unseat Shea-Porter: Frank Guinta, Rich Ashooh and Bob Bestani.