A top Trump volunteer in Massachusetts “will no longer have any involvement” in the campaign after he sent an email Sunday evening raising alarm about the Republican ticket’s chances in neighboring New Hampshire.

Tom Mountain, who had served as one of several vice chairs for the former president’s effort in Massachusetts, wrote in an email to Trump volunteers in the state that “the campaign has determined that New Hampshire is no longer a battleground state,” and advised supporters to instead direct their attention to Pennsylvania. The GOP had been bullish about winning New Hampshire before President Biden dropped out of the race.

In the email, Mountain, a former official with the Massachusetts GOP, said Trump was “sure to lose by an even higher margin” in New Hampshire than in 2016 and 2020, citing “campaign data/research.” He claimed resources would be suspended and the campaign would not send Trump or high-profile surrogates such as his sons. The email was obtained by the Globe and confirmed with multiple recipients.

Republicans in New England and the Trump campaign were quick to rebut Mountain’s email and dismiss him as a mere volunteer not privy to internal deliberations about campaign strategy or plans for a state that is not his own.

Brian Hughes, senior advisor to the Trump campaign, said to call Mountain a “leading volunteer” would be a “massive overstatement of his involvement” and added that “due to this ridiculous misrepresentation of our ongoing operation in New Hampshire, he will no longer have any involvement going forward.”

“This isn’t true,” Hughes said of Mountain’s email. “President Trump’s campaign maintains an on-the-ground presence in New Hampshire, including staff and offices, while Kamala Harris is parachuting in because she knows that the Granite State is in play. We look forward to building on the momentum that we have grown since the primary and sending New Hampshire’s four electoral votes to President Trump’s column on November 5.”

The Republican National Committee did not answer questions, however, about what resources it is sending to New Hampshire, or any plans for campaign events there. Trump has not appeared in New Hampshire since he won its first-in-the-nation primary in January, and it has been months since the state has had a visit from a top surrogate, such as North Dakota Governor Doug Burgum in April.

Steve Stepanek, who leads Trump’s campaign in New Hampshire, said Mountain “obviously has no idea what is going on in NH because he is from Massachusetts” but did not respond to further questions.

Even as Mountain’s message rankled many of his fellow Republicans, who complained he was uninformed or speaking out of turn, it underscored deep concerns among some in the GOP that having Vice President Kamala Harris at the top of the ticket makes Democrats more competitive in swing states such as New Hampshire. Mountain declined an interview request.

New Hampshire is a purple state, with a Democratic congressional delegation and a Republican governor, but it has not voted for a Republican for president in more than 20 years. This year, with Biden at the top of the ticket, the GOP there was optimistic about taking the state back for Trump.

But since Harris ascended to the top of the ticket and built new momentum on the Democratic side, the race in Republican reach states such as New Hampshire has appeared to tighten. A recent poll found Harris leading Trump in the state, and she is expected to appear in New Hampshire this week. The Cook Political Report recently moved the state from “lean” to “likely” Democratic, another indication of Harris’s strength there. Given that challenge, as well as how few electoral votes New Hampshire carries — just four — it may not be worth investing in, some New England Republicans quietly acknowledge.

Two leading Massachusetts Republicans told the Globe they were not aware of any shift in the Trump campaign’s strategy for New England.

Janet Fogarty, the Republican National Committeewoman for Massachusetts, said in an interview Sunday that New Hampshire is “an important state.”

She said Republican volunteers from reliably blue Massachusetts flock north to campaign in New Hampshire every four years, and she did not expect 2024 to be any different. Of Mountain’s email, she said, “there’s no there there.”

For his part, Mountain wrote in his email that “the Dems’ campaign shakeup from Biden to Harris led our campaign to shift strategy to other winnable battleground states.”

“So for those who were active in the NH ground campaign in 2016 and 2020, and expected to do the same after Labor Day, the simple question is… what are we to do?” Mountain wrote. “GO TO PENNSYLVANIA. The nearest battleground state. This is a must-win state. If we lose Pennsylvania we lose the election.”

A former vice chairman of the Massachusetts GOP, Mountain stepped down from the role in 2021 in the wake of what he called a “scurrilous and demeaning” blog post about his personal life.

Emma Platoff can be reached at emma.platoff@globe.com. Follow her @emmaplatoff.