Commonwealth heads fixed on climate change as their major topic ahead of a major summit on the issue in Copenhagen.

Leaders of the 53-nation group meeting in the Caribbean said they now have a chance to influence the global debate.

“What we can do is to raise our voices politically,” said Prime Minister Patrick Manning of Trinidad and Tobago, which is hosting the biennial meeting. “We feel can have some effect in influencing the discussions in Denmark.”

Others apparently agree. This year's meeting is drawing leaders from outside the Commonwealth such as Danish Prime Minister Lars Loekke Rasmussen, UN Secretary-General Ban Ki-moon and, most unusually, French President Nicolas Sarkozy. Mr Manning stressed that the leaders would not be negotiating the details of a climate treaty in their private meetings. Rather, they would be working out a statement that reflects a huge segment of world opinion, a quarter of the world's countries.

“A statement from countries as diverse as those that you find in the Commonwealth is a statement that would be much more reflective of world than would otherwise be the case,” he said.

Prime Minister Gordon Brown, also attending the meeting, has called for a strong statement warning of the economic and environmental dangers of letting climate change go unchecked.