British charities have launched a radio and TV campaign to raise funds for victims of the devastating floods in north-western Pakistan.
The appeal is being made by the Disasters Emergency Committee (DEC) - an umbrella organisation of 13 UK humanitarian aid agencies.
The UN says four million people have been affected by the floods, and at least 1,600 have died.
Donations can be made by phone, post, at Post Offices and banks.
The TV and radio appeal was presented by journalist and former British hostage in Lebanon, John McCarthy.
The DEC said aid from its members was now reaching more than 300,000 survivors.
DEC chief executive Brendan Gormley said the appeal was crucial "because of the scale of the tragedy".
"We saw what floods could do in Cumbria, but it's difficult to just conceive of hundreds of miles of homes destroyed, crops ruined and now - as the water recedes - everything covered in a thick slime."
Aid agencies are already working in the region, distributing clean water and food parcels, but "they want to scale up their work, so this is the way of going to the public and saying 'please help'," Mr Gormley said.
Further rain slowed the relief effort on Tuesday as aid agencies struggled to reach the thousands of people cut off by the floods, which hit the north-west of the country hardest.
They have warned that hundreds of thousands of people are awaiting help and there are shortages of food, clean water, shelter and medicine.
Amid concerns about the outbreak of diseases following the floods, there have been reports of cholera cases in the Swat Valley.
The director of policy at Save the Children, David Mepham, said people were using "ingenious" ways to get help through, including using helicopters, boats and donkeys.
He added that people could "feel very confident" their donations would be used to assist those affected.
In some affected areas, there were protests at the government's perceived inaction. The Pakistan army has defended its rescue operation.
Pakistan President Asif Ali Zardari is pressing ahead with his schedule of diplomatic visits to European nations, despite demands for him to return home.
The United Nations estimates 980,000 people have lost their homes in floodwaters or have been forced to flee, while the UN World Food Programme said some 1.8m needed food aid.
The UK government is sending 2,000 all-weather tents to affected districts in Pakistan, Secretary of State for International Development Andrew Mitchell has said.
He also said the Department for International Development (DfID) would enable humanitarian experts and aid agencies to travel quickly to affected areas, using emergency relief funding administered by the Consortium of British Humanitarian Agencies.
He added that the tents were in addition to £10m of aid money the government pledged for Pakistan on Monday.
The DEC charities are ActionAid, Age UK, British Red Cross, Care International, Cafod, Christian Aid, Concern, Islamic Relief, Merlin, Oxfam, Save the Children, Tearfund and World Vision.
The relief effort from DEC's charities includes the following action so far:
- Oxfam has helped 182,000 people by providing clean water and hot food. They have also deployed 17 emergency boats to assist government search and rescue efforts, evacuating 80,000 people.
- ActionAid is working with its partners to help more than 23,000 people in areas of the Punjab to distribute food including rice, sugar, pulses, oil and tea. Twelve medical camps have been set up there. In Azad Jammu Kashmir and Khyber-Pakhtunkhwa - which includes hard-hit areas of Swat and Swabi - it is providing sheets, mattresses and mosquito nets to displaced survivors.
- The British Red Cross has released £50,000 from its disaster fund to provide immediate relief, and help 35,000 families by distributing food and other supplies and working to provide water and sanitation.
- Care International has sent 11 trucks of emergency supplies to Khyber-Pakhtoonkhwa, including shelter for about 1,800 people, hygiene kits, kitchen sets and water purification tablets. It has set up eight mobile health clinics and is due to send shelter and supplies to other districts.
- Islamic Relief has delivered hygiene kits to 14,000 people as well as tents.