The deal on African aid agreed at the G8 summit is a "mighty achievement" for millions of campaigners worldwide, Prime Minister Tony Blair has told MPs.
Mr Blair saluted the organisers of Make Poverty History and Live 8.
Conservative leader Michael Howard praised the "substantial progress" but said impetus must continue on climate change and making trade free and fair.
Lib Dem leader Charles Kennedy said the G8 was only "treading water" on tackling global warming.
The G8 promised to boost aid to Africa by $25bn and cancel the debts of 18 countries.
No date was set for an end to farm subsidies, although Mr Blair said this could come at trade talks in Hong Kong in December.
$28bn increase in aid promised
UK to host a 1 November meeting on climate change, to assess progress
No date set for end to farm subsidies but Tony Blair predicts this will be agreed at trade talks in Hong Kong later this year
$3bn agreed for Palestinian Authority for investment in infrastructure
G8 commits to training 20,000 peacekeepers for Africa
African leaders to commit to democracy and good governance as part of the deal
Debts of the 18 poorest countries to be cancelled
The agreement has received a mixed reaction from aid campaigners while environmental groups say little was achieved on tackling climate change.
In a Commons statement, Mr Blair said delivering on the G8 pledges "would be the most poignant and powerful riposte to the forces of terrorism".
"This summit of itself cannot end poverty in Africa but it can mark a turning point," he said.
The UK hosted the summit in Gleneagles as part of its six-month presidency of the G8.
Mr Blair said that the deal was "the most detailed and ambitious package for Africa ever agreed by the G8".
But he warned African leaders had to improve standards of governance.
He said: "This is a partnership, not an act of charity. In the end, only Africans can lead and shape Africa."
Mr Blair said he could not understand claims that some of the aid cash had been promised before.
The "vast bulk" of the aid agreed at the summit was "new money", he said.
And he said the talks on climate change had established a "pathway" to an agreement after international divisions on the issue.
Mr Blair said he did not want to "oversell" what had been achieved on global warming but rejected Mr Kennedy's suggestion that it had only been "treading water".
There would be more talks later this year, he said.
Emerging economies like China and India must be included in a deal - otherwise it would be difficult to persuade people in developing countries to accept tough targets, he argued.
Tory leader Mr Howard said it had taken "political courage" to put climate change on the G8 agenda, although progress had not been as much as he would have liked.
"It is essential that the issue does not now drop down the agenda for the remainder of the year and beyond," said Mr Howard.
He said summits could never live up to the hopes put on them but there were prospects of further advances on both world poverty and climate change later this year.
He asked: "With Britain having secured a lasting legacy from its G8 Presidency on the matters of aid and debt, is it not essential that we work to secure a lasting legacy on trade and on climate change too?"
He pressed the prime minister on abuses by Robert Mugabe's government in Zimbabwe.
Mr Blair said what was happening in Zimbabwe was "abhorrent" but the issue would only be dealt with by pressure from nations in the region.
The summit's progress on aid issues was praised by Mr Kennedy but he stressed that the key test had yet to come.
The Lib Dem leader said: "The agreements made are not going to be judged by the promised made but by the promises that are in fact fulfilled."
On climate change, Mr Kennedy said there would not be "concrete progress" until there were new targets to replace the Kyoto deal, which the US refuses to sign.
Former Labour minister Michael Meacher raised fears that debts were being cancelled on conditions African countries opened up their markets.
But Mr Blair said the G8 was clear that African countries needed the capacity to trade effectively.