BOSTON — Governor Charlie Baker is throwing his support behind a proposal to ban motorists from holding cellphones while they drive.

The Republican governor endorsed the bill on Tuesday while also urging drivers to use caution and avoid distractions on the roads while traveling around Thanksgiving.

The bill passed the Senate in June but has not yet been taken up by the House. Baker has been non-committal about the legislation in the past, saying only that he would carefully review the bill if it reached his desk.

Under the proposal, motorists could only use their cellphones or other electronic devices with hands-free technology.

More than a dozen states, including New Hampshire, Connecticut, New York and Vermont have such laws in place.

Massachusetts bans texting while driving and all cellphone use by minors.