Speaker rules coal, solar 'undesirable'

A lump of coal and a solar panel are both "undesirable" in federal parliament, Speaker Tony Smith has told MPs

Last week Treasurer Scott Morrison brought into the House of Representatives chamber a lump of Hunter Valley coal to make a point about electricity reliability.

On Monday, Greens MP Adam Bandt waved a solar panel in question time, telling parliament it "does quite well in a heat wave".

A clearly disgruntled Speaker said the lump of coal and solar panel were both "undesirable props" and he would not allow such stunts to continue

"Like a game of musical chairs, that's it - any further repetition of it I'll need to deal with," he said.

"I find it quite unbecoming of the house."