State Rep. Matt Muratore, a Plymouth Republican, said Tuesday he is running for the Plymouth and Barnstable Senate seat, putting to end weeks of speculation about whether the five-term lawmaker would jump into the race.

Muratore pitted himself against Rep. Dylan Fernandes, a Falmouth Democrat who last month drew an endorsement from Gov. Maura Healey and Lt. Gov. Kim Driscoll, the former mayor of Salem.

The key matchup, which also includes Bourne School Committee member Kari MacRae, will again test the Massachusetts Republican Party’s ability to flip a Senate seat after winning a Central Massachusetts district last year and the Democratic State Party’s strength on the South Shore and Cape Cod.

Muratore pointed to an “affordability crisis” in Massachusetts affecting housing, healthcare, education, and the cost of living. And he also touched on what has become a rallying cry for the Republican party in Massachusetts — immigration and the state’s decades-old right-to-shelter law.

“We are also facing an unprecedented fiscal burden from the costs imposed by loopholes in the state’s 40-year-old right-to-shelter law.  The immense burden is due to the tremendous surge of migrants into our state which is straining our housing, health care, and education systems beyond their capacity,” he said in a statement.

The race to fill the Plymouth and Barnstable Senate seat — which covers Bourne, Falmouth, Kingston, Mashpee, Pembroke, Plymouth, Plympton, and Sandwich — kicked off after incumbent Sen. Susan Moran said she would not seek reelection to the Legislature to instead pursue an elected county post.

Muratore enters the Senate race with more than $21,700 campaign cash on hand, according to finance records last updated at the start of January. Fernandes reported more than $122,000 cash on hand as of Jan. 2, according to the state’s campaign finance office.

Fernandes, who has also drawn the support of some dozen lawmakers on Beacon Hill, did not immediately respond to a request for comment.