The Earth summit has transformed the global agenda, Tony Blair insisted on his return from South Africa.

Responding to hostile headlines over the Johannesburg conference, the prime minister said that the environmental issues had travelled from rhetoric to reality following the summit.

Praising the UN for working "flat out round the clock with real dedication and commitment" Blair warned the press that summits should not be dismissed as global talking shops.

"I know there has been some comment about what these summits mean, what follows through from it, but without the Rio summit there would not have been action on climate change that means this country is reducing our greenhouse emissions substantially," he said.

Harking back to previous Earth summits over the last decade, Blair argued that without the talks there would not have been "massive" increases in development aid to the world's poorest countries.

"For the new partnership for Africa, there would not have the additional commitment of funds, the cancellation of debt, and one the most exciting things that has happened recently has been progress in whole series of conflicts from whether in Angola, the Democratic Republic of Congo and to an extent in the Sudan - all that arose out of summits where agreements were concluded," he said.

After the Johannesburg headlines die away, said Blair, the momentum must be kept up to continue translating conference agreements into action on the ground.

"We now need to happen is that we keep the agenda moving forward and make sure that the principles are actually translated into genuine change on the ground."

"We're moving in a direction, the direction is towards a new form of development, which is a partnership, and the direction is towards combating climate change," he later added.

However, the prime minister warned that "corrupt" African regimes, such as Zimbabwe, would not receive help from the wealthier west.

"We will help regimes with a proper governance, a proper system of working, but we're not going to be shelling out money to regimes that are corrupt, or treat their people badly," he said.