A Darwin man has been handed a suspended prison sentence for smashing up the electorate office of former Northern Territory Chief Minister Michael Gunner.

Paul Holland, 47, pleaded guilty in the Darwin Local Court on Monday to damaging property, unlawful entry and being armed with an offensive weapon during the attack in July last year.

The incident happened days after Mr Gunner quit politics following the birth of his second child.

Mr Holland told the court he felt he was living through a "nightmare" at the time because of the COVID vaccination mandate policy that Mr Gunner had introduced.

He agreed with the facts laid out by prosecutors, who said Mr Holland had smashed the window of the Parap office before entering to damage computers and other office equipment.

Mr Holland told the court the incident might have been the result of a psychotic episode and that he had stopped using drugs the month prior.

"I was seeing some pretty crazy shit in my mind, building up to this," he said.

"The nightmare the government's put us through the last couple of years — there'd be lots of people like me, even now, tearing their hair out thinking 'where am I now?'"

During the height of the pandemic, the NT government mandated COVID-19 vaccinations for the vast majority of workers as part of efforts to reduce the impact of the virus on the Northern Territory.

Judge Elizabeth Morris sentenced Mr Holland to seven months in prison.

She suspended the sentence based on his compliance with bail conditions and because he had endured difficult conditions in Darwin's over-crowded prison while on remand for over three months.