Former state Sen. Richard Tisei, a Republican, announced on Monday that he has formed an exploratory committee for a rematch with Rep. John F. Tierney in Massachusetts’ 6th District.

Republicans anticipated Tisei was eyeing another run against Tierney, the vulnerable Massachusetts Democrat who squeaked out a win last year by a 1-point margin.

“The creation of this committee will allow me to more actively explore a potential campaign for the 6th Congressional Seat in the 2014 midterm elections.  I hope to be able to make a formal announcement regarding my plans later this Fall,” Tisei said in a news release.

Tierney is again considered one of the most vulnerable members of the House. A GOP poll from August found that Tisei and Tierney would be in a statistical dead heat in a potential rematch.

Tierney far underperformed President Barack Obama, who carried the district by an 11-point margin in 2012.

Tierney is also facing a primary challenge from Democrat Seth Moulton, a veteran who outraised Tierney in the third quarter.

Massachusetts’ 6th District is currently rated a Lean Democrat contest by Rothenberg Political Report/Roll Call.