An MP landed herself in hot water with Commons Speaker John Bercow after holding up a poster demanding "climate action" from the Government during Prime Minister's Questions.
The Green Party's Caroline Lucas (Brighton Pavilion) was told to stop being pre-occupied with her own views after holding up a poster featuring photographs and the statement Brighton Demands Climate Action.
Mr Bercow said if every MP held posters up for their different causes during debates it would make a mockery of Parliament and that her conduct was "disorderly".
It is not the first time Ms Lucas has been admonished in the Commons - last year she was reprimanded for wearing a T-shirt emblazoned with the slogan No More Page Three during a debate and told to cover up.
After her question on whether Prime Minister David Cameron would attend the UN climate change summit later this month, the Speaker intervened: "Can I just say for future reference it is disorderly to display images in that way.
"All courtesy to you, whose principled commitment I respect, but if everybody did that on every cause it would make a mockery of this place.
"I ask you to take a view much wider than her own immediate pre-occupation."
Following the question session, Ms Lucas tweeted: "It's not holding up poster that makes mockery of Parliament but jeering, planted Qs + the failure to act on climate, biggest threat facing us".
In the Commons chamber, Ms Lucas had asked : "I welcome suggestions that the Prime Minister will attend the crucial climate summit at the end of this month.
"Will you confirm that the Prime Minister will go and will you tell us what bold new initiatives the Prime Minister will be taking with him?
"Because that's what my constituents in Brighton say they want, they want to protect what they love. They want urgent action on climate change."
Replying on behalf of the PM, who is in Scotland, Commons Leader William Hague replied : "The answer is that the Prime Minister will attend the UN General Assembly later in September.
"We haven't yet issued or finally decided his precise schedule but of course we're looking at attendance at the meeting that you refer to and Britain will continue to play a leading role in the world in bringing about a legally binding agreement on climate change.
"The next 15 months is a very, very important period on this leading up to the meeting in Paris at the end of next year.
"We are one of the most active countries in the world in climate change diplomacy and the Prime Minister and other ministers in New York will be fully conveying that, whoever attends the meeting."