The Conservatives have pledged to spend £500m a year of the UK's foreign aid on tackling malaria in sub-Saharan Africa.
Shadow chancellor George Osborne said the funding would continue until a UN target of reducing the incidence of the killer disease was met.
He told BBC Radio 4's Today programme malaria did not get the same international attention as Aids but it was "killing 3,000 children a day".
"And the dramatic point is that we could stop it," said Mr Osborne.
Mr Osborne unveiled the policy in a speech in Ugandan capital Kampala as part of a three-day visit alongside former UN special advisor, Professor Jeffrey Sachs.
He said the "unprecedented" contribution by a single country was a third of the entire sum believed to be needed by the World Health Organisation to defeat the disease.
"I hope that other nations follow our lead, and join us as we fight to make malaria deaths a thing of the past. Let our generation stand up and say: we won the war against malaria," said Mr Osborne.
The Conservatives have already pledged to meet a UN target of dedicating 0.7% of national wealth to overseas aid by 2013.
The party said the spending would represent a "significant increase" on present government funding for the fight against malaria.
Oxfam welcomed the move but called on the Conservatives to support their claim that privatised health services are not the solution for developing nations.
The Department for International Development said it did not provide figures for spending on individual diseases such as malaria or Aids because funds were channelled through aid agencies.