A councillor and magistrate has refused to resign for posing with an AK-47 rifle and posting a picture on Twitter.
Derby Liberal Democrat Ajit Atwal has apologised for the photograph, which was taken on holiday in India, but said he had "done nothing wrong".
Leader of Derby City Council, Paul Bayliss, called on Mr Atwal to "reconsider" his positions after a national newspaper published the photo.
Mr Atwal said he had been naive, but had not committed a crime.
He said a politician friend in India allowed him to pose with a bodyguard's assault rifle while he was visiting the country in September.
Labour councillor Mr Bayliss said: "He's in a position in the public eye. He needs to exercise judgement whether he's in this country or not.
"This suggests to me he doesn't exercise very good judgement and I think he needs to reconsider his position as both a councillor and a JP (justice of the peace)."
Mr Atwal said the picture could be viewed on his Twitter profile for seven months before he took it down.
He said Mr Bayliss's criticisms and the story's appearance in The Sun were "politically motivated".
"Looking back now, I probably was a bit naive," he said.
"What crime have I committed? I was 6,500 to 7,000 miles away. It was not official business.
"Where's the gross misconduct? What have I done wrong?
"I am up for election this year. It's politically motivated. I am just trying to be discredited."
A spokesman for the Liberal Democrats said: "Mr Atwal removed the image from his Twitter feed before being asked to do so by the party.
"Derby City Liberal Democrats has also launched its own investigation into the matter."
Mr Atwal apologised if he had "caused anyone any alarm or distress".