Republican Richard Tisei, a former state Senate Minority Leader and GOP nominee for lieutenant governor, announced his candidacy for Massachusetts’ 6th district on Tuesday.

Eight-term Rep. John Tierney (D), whose wife was convicted on federal tax charges last year, is considered the most vulnerable incumbent in the state’s all-Democratic delegation. Plugged-in Republicans see Tisei as the most likely candidate to beat Tierney. Tisei will face attorney Bill Hudak, who lost to Tierney in 2010, in the GOP primary.

“The people of this district are independent-minded and deserve an independent-minded congressman who will put them first,” Tisei said, according to a prepared copy of his remarks.

Under a new redistricting map, which is likely to be signed into law soon, the 6th district gained the towns of Tewksbury, Billerica and a part of Andover. All three municipalities voted for now-Sen. Scott Brown (R) in the 2010 special election. In the 2008 presidential election, Tewksbury went for Sen. John McCain (R-Ariz.), while Billerica and Andover voted for Barack Obama.