Polar Bears and supporters of I Count, the campaign of Stop Climate Chaos, visited Downing Street on Monday to hand in 150,000 petition cards demanding the UK Government does all it can to tackle climate change.

The visit comes as Environment Secretary Hilary Benn delivered a disappointing response to a public consultation on the Climate Change Bill.

The I Count delegation to Downing Street aims to draw attention to the shortfalls in the draft Climate Change Bill and their visit marks the beginning of a six month campaign which will see climate change campaigners all over the country lobby their MP to ensure a Climate Change law is passed which works.

Anita Payne, who has worked with Tearfund in Malawi and Liberia, was one of the five visiting Downing Street.

"Poor communities around the world are already at the sharp end of climate change, with flooded homes, increasingly barren and drought-hit land," she said. "I've seen the effects for myself in Africa when I was with Tearfund helping local churches to respond to recent droughts."

She added, "I'm here at Downing Street today because I believe that God requires us to love justice and live justly. We need to be good stewards of God's earth and good neighbours to each other, not pushing poorer people into deeper poverty but living more sustainably, for everyone's benefit."

In a separate event at Kew Gardens earlier on Monday, Environment Secretary Hilary Benn announced changes to the proposed Climate Change Bill, in response to a public consultation on the draft legislation.

However Rachel Roach, Tearfund's Climate Change Adviser, believes these changes still fall short of what's required for a robust climate change law.

"While today's changes are a step in the right direction, the Government has failed to take the bold steps required to seriously tackle climate change. While the Government proposes a 60 per cent cut in carbon emissions by 2050, the legislation must adopt the widely accepted 20C global warming danger threshold and cut CO2 emissions by at least 80 per cent by 2050."

She added, "This Bill is a major opportunity for the UK to demonstrate international leadership but at the moment the Government's credibility is in question. They say they support the 20C target but are failing to translate their words into action. Bold action and strong leadership are required in the lead up to international climate change talks in December."

The Climate Change Bill will be the first of its kind in the world when it is introduced to Parliament in the Queen's Speech on November 6. The first draft of the legislation was introduced by the Government in March following pressure from I Count and other climate campaigners. The Bill is likely to receive its second reading in December before being voted on by MPs in spring 2008.

During the crucial next six months, I Count supporters will be lobbying their MPs to ensure the UK delivers a bold Bill in line with the UK's fair share of the international effort to prevent exceeding the global warming danger threshold of 20C.

According to Tearfund, the Government must increase the carbon dioxide reduction target from 60 per cent to at least 80 per cent by 2050, and ensure that emissions from international aviation & shipping are included in the reduction targets.

It also called on the Government to set binding carbon budgets with annual milestones, to make sure that emissions reductions are on track.

Alex Robertson, Deputy Head of Policy at the Catholic aid agency CAFOD, also called for greater commitment, saying that the current Bill "falls short of the mark by ignoring strong scientific evidence".

He echoed Terfund's call for carbon emissions to be reduced by at least 80 per cent by 2050.

"Any delay in setting these stronger targets will mean that precious time is lost.," he warned.

"The UK Government is setting too low a standard with this current Bill. Stronger measures are needed if the UK is going to contribute towards stabilising global temperature warming at 2°C.

"People living in poverty will be amongst those most affected by climate change. They have done the least to cause the problem, but will suffer the harshest effects and have fewest resources to adapt.

"Adequately tackling climate change is essential if the UK's good work towards fighting poverty is not to be washed away by rising global temperatures."

Groups will be collaborating on lobbying activity through the I Count Community Groups Map, an online networking tool (http://www.icount.org.uk/groupsmap) launched in September 2007 with 350 groups. The number of groups joining to host themselves on the site has risen to 450 so far and this is set to increase as word spreads.

The Stop Climate Chaos coalition, of which Tearfund is a member, comprises international development, environment and faith-based NGOs, as well as women's organisations, trade unions and community groups.