Christian Aid and its overseas partners met at the House of Commons for a special Parliamentary meeting on climate change.
MPs were warned by the charity that unless the UK Government commits to reducing emissions by at least 80 per cent, millions of people in the developing world will suffer by 2050.
The meeting was organised by MP Alan Campbell ahead of Christian Aid's 1,000-mile Cut the Carbon March.
During the meeting, Campbell briefed constituency representatives on the political messaging behind the protest.
The Cut the Carbon March is expected to be the longest ever protest March in the UK.
The goal is to gather support for changes to the new Climate Change Bill, which will enter Parliament for discussion six days after the end of the March in October.
Christian Aid is calling on the UK Government to ensure the new Climate Change Bill includes a target for UK CO2 emission cuts of at least 80 per cent on 1990 levels by 2050 "so we play our fair part in keeping global warming below 2˚C", said Christian Aid.
It also wants to see the introduction of mandatory reporting of CO2 emissions by companies trading in the UK.
Mr Campbell said: "I am pleased to support Christian Aid's Cut the Carbon March. The draft Climate Change Bill is the first of its kind in the world and demonstrates that Britain is leading the way on environmental issues.
"It's testament to the campaigning skills of groups such as Christian Aid that environmental issues have caught the public imagination and events like these are vital in raising awareness of the issue and show that important though government and international action is, it's vital that every individual plays their part to ensure we create a sustainable environment for future generations."
The Cut the Carbon March is backed by celebrities including singers Lemar and Amy Macdonald and actors Leonardo Di Caprio and the rising star from the latest Harry Potter instalment, Katie Leung. The 11-week trek across the UK will kick off in Northern Ireland and end in London on 2 October 2007.
The 18 'core' walkers to complete the entire distance come from the UK and developing countries that Christian Aid is helping to adapt to climate change, such as Kenya, South Africa, the Democratic Republic of Congo, Brazil, El Salvador, Bangladesh, Philippines, and Tajikistan.
