Man hurls abuse at minister in Senate

A man has been thrown out of the Senate's public gallery for hurling abuse at Agriculture Minister Bridget McKenzie.

The man yelled "F***ing useless!" at Senator McKenzie during Question Time on Monday amid calls from angry farmers to ditch the Murray-Darling Basin Plan.

He was swiftly escorted from the chamber.

"That's utterly inappropriate behaviour. I will not tolerate interjections from galleries. It's impolite to other citizens who are also here," Senate President Scott Ryan said.

A group of about 50 people cheered and applauded after One Nation senator Malcolm Roberts asked Senator McKenzie whether she would resign over her "failure" to help agriculture.

"No, Senator Roberts, I won't be resigning," the Nationals deputy leader replied.

An outbreak of interjections from the public prompted the usually reserved Senator Ryan to ask if one of the men had the courage to own up.

"You calling me a coward? You're a coward," one man said before he was marched out.

Senator Ryan was unimpressed with the outburst.

"It is completely disrespectful to your fellow citizens to behave that way," he said.

The group staged a mass exodus shortly after, as Senator McKenzie answered a "Dorothy Dixer" question about the government's support for drought-affected farmers.

A convoy of farmers has descended on Canberra to urge the Morrison government to scrap the basin plan.