Officials say people cannot go back to areas where landmines remain
BBC News, Colombo
The UK says it will soon withdraw all but emergency funding for the camps where about 250,000 displaced Tamils are confined in northern Sri Lanka.
The announcement came after the UK Development Minister Mike Foster visited the biggest camp at Menik Farm.
He said 70% of people should be able to leave and stay with host families.
Refugees say conditions are poor, with inadequate drinking water and drains, and illness due to the hot conditions. Many are pleading to be allowed home.
Earlier, Sri Lanka's government said it was taking measures to ensure the camps could cope with the onset of monsoon rains.
'Send us home'
Mr Foster said that once the imminent monsoon was over, the UK government would only fund life-saving emergency interventions in the camps.
The minister described the sites as "closed" as their inhabitants cannot freely leave.
Refugees say conditions are poor, with inadequate drinking water and drains
Sri Lanka's government has said it is installing adequate drainage to ward off any flooding. But the UK, the UN and others disagree.
Visiting Menik Farm, Mr Foster said he feared heavy rainfall might cause devastation and spread disease.
He said some 70% of the camp-dwellers could leave and stay with host families.
The BBC was able to meet refugees who clamoured to talk about their situation.
One woman after another said the conditions were poor - that there was no good drinking water, that the drainage system could not cope, and that people were falling ill in the hot weather.
"Please send us home as soon as possible," one said.
Media access to the camps, and the north of the island in general, has become rare, but the army which is in overall charge of the refugee facility did not stop the BBC having brief but spontaneous meetings with people.
The former military commander of the camp, now governor of the Northern Province, defended the slow progress of refugee releases, saying people could not just go back to areas from which landmines had not yet been cleared.
The government says about 240,000 people remain in Menik Farm, and that more than 20,000 have been resettled or released. This figure also includes those who have died.