The Republican congressman who assaulted a Guardian reporter has failed to honour a commitment made in court to grant the reporter a one-on-one interview.

In June Greg Gianforte pleaded guilty to a misdemeanor assault charge for “body-slamming” Ben Jacobs.

In a civil settlement, the Montana Republican made a $50,000 donation to the Committee to Protect Journalists and issued an apology letter.

In the courtroom, Gianforte pledged to sit down with Jacobs in Washington DC after Jacobs expressed his hope for an interview in his victim’s statement.

“I’m sorry, and if and when you’re ready, I look forward to sitting down with you in DC,” Gianforte said.

However, in the weeks and months that followed, Gianforte’s staff have refused requests for an on-the-record interview with Jacobs, offering an off-the-record meeting instead.

“In refusing to do the promised on-the-record interview with me, Congressman Gianforte continues his pattern of avoiding responsibility for his actions and refusing to live up to the statements made in what I had thought was a sincere apology,” Jacobs wrote in an email to Gianforte’s communications director Travis Hall.

“He has refused to explain why he slandered me, he unsuccessfully tried to avoid pleading guilty to a physical attack against me and he also unsuccessfully fought a legal battle to avoid the mild inconvenience of having a mugshot taken.”

Gianforte’s office responded in a statement on Tuesday evening.

“As he has since June, Congressman Gianforte has offered to sit down with Mr Jacobs,” a spokesman said.

“For anyone to suggest otherwise is false. We have been honest brokers in our efforts to arrange for Mr Jacobs to sit down with the congressman, including providing Mr Jacobs with possible dates and times for a meeting and asking what Montana beers the congressman could bring for Mr Jacobs when they meet. Mr Jacobs has yet to either accept or decline our offer. Congressman Gianforte’s offer to Mr Jacobs remains on the table.”

Gianforte’s assault on Jacobs happened after the reporter approached him to ask a question about the Republican healthcare bill. The then candidate threw him to the ground and began punching him.

Though the Gianforte campaign initially blamed Jacobs for the altercation, an audio recording and the first-hand account of one of three Fox News reporters who witnessed the assault contradicted the campaign’s statement.