BOSTON (CBS/AP) – Massachusetts Gov. Charlie Baker will run for re-election, according to his senior political adviser.

The Republican was widely expected to seek a second term in 2018 with Lt. Gov. Karyn Polito.

READ MORE: Red Line Train Derails At Broadway MBTA Station

Confirmation came Tuesday from Jim Conroy, who managed Baker’s 2014 campaign. Conroy said Baker will not formally launch his re-election campaign until next year.

Baker has consistently ranked among the most popular governors in the country, with an approval rating of nearly 70 percent according to a recent Morning Consult poll.

He told WBZ-TV political analyst Jon Keller in a recent interview that he’s proud of the job his administration has done working with both Republicans and Democrats.

READ MORE: Andrea Campbell Seeking Commitments Before Endorsing Mayoral Candidate

“We have good relationships with our colleagues on both sides of the aisle, good relationships with our colleagues in local government. We built a bipartisan cabinet,” he said.

The governor has maintained a brisk fundraising pace. His campaign account reported a mid-November balance of just under $7 million.

Three Democrats — Newton Mayor Setti Warren, former Patrick administration secretary Jay Gonzalez and environmentalist Bob Massie — have all announced campaigns for governor.

Baker’s first campaign for governor was in 2010 when he lost to incumbent Democratic Gov. Deval Patrick. He won the GOP nomination again in 2014 and narrowly defeated Democratic Attorney General Martha Coakley in the general election.

MORE NEWS: Inspired By Mother, NH Teacher Running Virtual Boston Marathon For Stepping Strong Center

(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)