A massive effort is needed by developed countries to meet targets for ending poverty, the chancellor told MPs on Tuesday.

Gordon Brown told the international development committee that developed countries will have to find $51 billion by 2015 if ambitious targets agreed at the UN financing for development summit are to be achieved.

"There is no doubt about the scale of the added costs that will have to be met if we are to meet out Millennium goals," Brown told MPs.

The resulting Monterrey Consensus was the first-ever UN conference to achieve clear commitments from the US and EU to increase overseas development aid.

At the summit the UK and other countries agreed to give 0.7 per cent of GDP to development.

"The interesting thing about what has happened over the last few weeks and months is that for the last 20 years aid has been going down. These two commitments by Europe and America are a reversal of the trend," said the chancellor.

International aid minister Clare Short assured the committee that other areas of her department's work would not be affected because of the focus on debt relief.

She said DfID was focused on ensuring resources were targeted to achieve maximum impact.

"We increase our public confidence in aid when we show that we are doing well with what we've got," the international development secretary said.

She also told MPs that there a more radical approach to helping developing countries was now being pursued.

Aid was no longer tied to buying equipment or expertise from developing countries.

"A lot of aid, including the EU, was deployed on projects that don't bring reform. We are now deploying aid in ways that don't have a massive bureaucratic tale," Short said.

The minister said that reform of political systems which were dogged by corruption would be necessary. But she stressed that aid would not be cut off to those countries slow or immune to political reform.

"You mustn't turn your back on non-reforming countries. You can't turn your back on the poor of the world," she said.