A New Mexico official was removed from elected office on Tuesday for his role in the January 6 siege on the US capitol, marking the first time a politician has lost their job for their involvement in the attack.

Couy Griffin, one of three commissioners in Otero county in southern New Mexico, was immediately removed from his position and cannot hold elected office again, Francis Mathew, a district judge in Santa Fe, wrote in his ruling.

The 14th amendment to the US constitution bars anyone who has participated in an insurrection from holding elected office. In June, Griffin was sentenced to 14 days in jail and a $3,000 (£2,604) fine for misdemeanor trespassing during the Capitol attack.

“Mr Griffin’s crossing of barricades to approach the Capitol were overt acts in support of the insurrection, as Griffin’s presence closer to the Capitol building increased the insurrectionists’ intimidation by number,” Mathew wrote in his ruling. “Mr Griffin aided the insurrection even though he did not personally engage in violence. By joining the mob and trespassing on restricted Capitol grounds, Mr Griffin contributed to delaying Congress’s election certification proceedings.”

Griffin told CNN he was “shocked” at the ruling and accused Mathew of being “tyrannical”.

“I’m shocked. Just shocked,” Griffin said. “I really did not feel like the state was going to move on me in such a way. I don’t know where I go from here.”

Earlier this year, Griffin sought to block Otero county, which voted overwhelmingly for Donald Trump in 2020, from certifying its official primary election results, citing concerns – which have been debunked – about voting machines.

The state supreme court eventually ordered the three-member commission to certify the election, which it ultimately did with a 2-1 vote. Griffin was the lone holdout.

“My vote to remain a ‘no’ isn’t based on any evidence, it isn’t based on any facts. It’s only based on my own gut feeling, my own intuition, and that’s all I need,” he said at the time.

Tuesday’s decision marked a major win for watchdog groups that have sought to use the constitutional provision to block members of the US Congress who sought to prevent the delayed certification of Joe Biden’s victory in the 2020 election.

Extremist supporters of Donald Trump caused the delay after invading the Capitol to try to prevent the certification. The insurrection is still under congressional and federal criminal investigation.

An effort to remove Marjorie Taylor Greene, the far-right Georgia congresswoman, from the ballot failed earlier this year. A similar effort seeking the removal of Arizona representatives Andy Biggs and Paul Gosar, as well as Mark Finchem, a Republican running to be Arizona’s top election official, also failed.

Tuesday’s decision marked the first time since 1869 that a court removed an election official for participating in an insurrection, Citizens for Responsibility and Ethics in Washington , a watchdog group that represented New Mexico citizens seeking to remove Griffin from office, said in a statement.

“This decision makes clear that any current or former public officials who took an oath to defend the US Constitution and then participated in the January 6th insurrection can and will be removed and barred from government service for their actions,” Noah Bookbinder, the group’s executive director, said in a statement.