Threats of violence against ministers are never acceptable, but voters are growing angry at the government, Labour leader Andrew Little says.
Ministers have been subjected to threats and insults lately, often with a sexual undercurrent.
Senior Cabinet Minister Paula Bennett said she had reported threats made against her to the police about once a month, including one calling for her to be shot at her next public event.
Mr Little said such threats had no place in politics.
But he said some people were getting tired of the government's spin.
"The sort of comments that are being made to me are very clear, and the sense of frustration and exasperation are very clear to me and I wouldn't be doing my job if I didn't make that part of my comment," he said.