Their claims are borne out by a report into emergency relief from the Overseas Development Administration (ODA) published today by the National Audit Office, the public spending watchdog.
The ODA, says the report, reacts quickly to sudden disasters like earthquakes and cyclones 'but take longer to satisfy themselves about the needs of slow-onset disasters' like famine and drought.
June Wyer, the co-financing officer for Christian Aid, said an application to the ODA for sums under pounds 50,000 were still taking one to two weeks but larger sums were taking several months.
In August, Christian Aid asked for pounds 100,000 to finance the restocking of livestock for refugees returning to Eritrea from Sudan. Usually, permission would be given within two months. Now, the charity did not expect to obtain approval until the new year. Another Christian Aid application, to assist refugees returning to Mozambique, was also predicted to take several months.
Ms Wyer said Yugoslavia now accounts for the same amount of aid as the whole of Africa combined. By refusing to grant more money to cover Yugoslavia, she claimed, the Treasury was causing other parts of the world to suffer.
This financial year, the ODA will give pounds 172m to Yugoslavia, and has been forced to drain its reserves.
An ODA source acknowledged yesterday: 'Maybe we are applying stricter criteria on some grants - Yugoslavia has put all our budget under pressure.'
Instances uncovered by the NAO include:
The ODA taking 142 days to approve a request from Save the Children to provide household items, tools and vehicles for the Angolan drought;
An ODA initial response time of up to 62 days;
A cargo of lentils taking 13 months to reach Eritrea;
Trucks taking up to nine months to be delivered to Ethiopia;
400 tonnes of ODA-financed vegetable oil packed in plastic containers - as opposed to tin drums - which leaked as they sat in the Ethiopian heat.