The "unprecedented nature" of the public response to an appeal to help people in flood-ravaged Pakistan will be revealed today.
They were the worst floods to hit the country for decades, with about 1,500 people killed and an estimated 20 million left homeless.
Donations to the Disasters Emergency Committee (DEC) have reached £24m, according to its website, but the most up-to-date figure is to be revealed today.
Brendan Gormley, chief executive of the DEC, will outline the scale of the public reaction to the floods, which affected a fifth of Pakistan, at a news conference at the BT Tower in London.
There were initial fears that the public had been slow to respond, with the DEC saying donations had been higher after the Haiti earthquake earlier this year.
A DEC spokesman said the appeal had unfolded in a "unique" way however, and added: "More than two weeks since the first appeals for the Pakistan floods were broadcast, the DEC will reveal the exceptional nature of the public's support for this appeal."
Deputy Prime Minister Nick Clegg previously suggested donations from the public may be muted as people were "struggling to understand" the scale of the crisis.
He said the world response to the floods had been "absolutely pitiful". United Nations secretary general Ban Ki-Moon also urged the international community to step up aid pledges after visiting the affected areas and describing it as the worst natural disaster he had ever seen.
Aid agencies have warned that six million children in flood-ravaged areas were at risk of life-threatening diarrhoea-linked diseases, malnutrition and pneumonia.
Doctors also fear that stagnant flood plains in densely populated, poverty-stricken urban areas could become breeding grounds for cholera, mosquitos and malaria.
The DEC, an umbrella organisation representing 13 leading UK aid agencies, is coordinating the appeal for victims of the flood.
To make a donation people can call the 24-hour hotline on 0370 60 60 900, visit http://www.dec.org.uk or donate over the counter at any post office or high street bank, or send a cheque.
They can also donate £5 by texting the word GIVE to 70707.Reuse content