Former State Rep. Geoff Diehl, a conservative Republican, announced Sunday that he will run for governor against incumbent Republican Charlie Baker.

Diehl is the first official Republican candidate in the race; Baker has not yet said whether he plans to run for reelection next year.

Diehl, who was part of Donald Trump's campaign effort in Massachusetts in 2016, entered the race with a statement deeply critical of restrictions imposed by Baker to combat the COVID pandemic.

“The pandemic response of a total shut down of the economy, followed by arbitrary federal, state and local regulations only made it harder for the small businesses to stay alive, especially in the restaurant and hospitality industries," Diehl said. "And I remain mystified how the big box stores like Home Depot remained open while your local hardware store was forced to close. Let that chapter of our state’s history remain a powerful example of what can never happen again.”

Diehl also said he is opposed to the multi-state Transportation Climate Initiative signed by Baker last year to cut climate change emissions from vehicles. "The last thing working families in Massachusetts need is added cost to commuting, food and goods that are already being hit by the inflationary effects of massive federal spending," he said.

In January, Diehl suggested Baker should be censured by the Mass. GOP for supporting Trump's impeachment after the Jan. 6 assault on the U.S. Capitol.

In 2018, Diehl was the GOP canidate for U.S. Senate, but he collected less than 40% of the vote statewide in his unsuccessful challenge to incumbent Democratic Sen. Elizabeth Warren.

Polling earlier this year suggested that Baker would still be the favorite for the GOP nomination if he chooses to run, with strong support among Republicans and unenrolled voters who can vote in the primary.

So far, four Democrats have entered the gubernatorial race: Harvard professor Danielle Allen; state Sen. Sonia Chang-Diaz; former state Sen. Ben Downing; and political newcomer Orlando Silva of Shrewsbury.