Environment Minister Sammy Wilson was today accused of becoming increasingly isolated after his party leader effectively dismissed his views on climate change.
Sinn Fein today said it would be impossible for the DUP to keep Mr Wilson in the post given his continued belief that mankind cannot be blamed for global warming.
The Environment Minister today repeated his controversial views, days after Mr Robinson said it was government policy and party policy to combat climate change.
Sinn Fein Environment spokesman Daithi McKay said: "I welcome the fact that Peter Robinson supports the Sinn Fein position on the causes of climate change and that he has given his Environment Minister a 'slap on the wrist' for his recent behaviour.
"The joint First Ministers both recognise that climate change is 'one of the most serious problems facing the world' and for Sammy Wilson to robustly challenge that position today is in itself a challenge to his own party leader."
On Monday in the Assembly Mr Robinson said climate change policies were written into the Programme for Government and he effectively tackled his Environment Minister's contention that man is not to blame for global warming.
"I think the scientific evidence is on the side of those of us who believe that man is having an impact on climate and therefore there is a necessity on the part of the Executive to be dealing with those issues," said Mr Robinson.
He added: "And even if it weren't so, I have to say the possibility that it were, should be enough to alert any responsible Executive to take whatever measures it can."
Mr Robinson said climate change "is a serious problem facing the world".
"The position as outlined in the Programme for Government directly flows from the DUP manifesto of 2007 to which all the people in this party are obliged to keep and to uphold," said the DUP leader.
He added: "I really don't care too much whether there is a (scientific) consensus or not, I just believe that it is still appropriate for us as an Executive to take action to prepare for any potential eventuality."
Today Mr Wilson repeated his belief that the scientific evidence was not conclusive and he questioned whether money spent on fighting climate change could be better spent on public services.
"For the vast majority of people... the discussions are about the real day to day problems that people face," said Mr Wilson.
He said of global warming: "I don't believe it's one of the most serious problems facing the world at all."
Mr Wilson said his party and the members of the Executive had a right to hold different views on the issue of climate change.
But Sinn Fein's Mr McKay said: "Peter Robinson has now indicated that the debate on the causes of climate change within the DUP is now over.
"Will he now demonstrate this position by ensuring that Sammy Wilson ceases to undermine what is obviously the accepted position not only of his own party leadership and the Executive but of the vast majority of people?"