The charity Oxfam said the stricken country faced a public health catastrophe unless clean water and sanitation was quickly provided.

The Burmese military junta has been criticised for not allowing emergency supplies and skilled aid workers into the secretive south-east Asian country quickly enough.

Foreign Secretary David Miliband blamed the "malign neglect" of the Burmese regime for turning the disaster into a "humanitarian catastrophe of genuinely epic proportions".

And aid agencies fear the crisis could deteriorate further, as rainstorms were set to lash the already deluged region later last night.

It is feared the sluggish response to the crisis could result in a death toll dwarfing the devastating Boxing Day tsunami which killed 250,000 people.

An estimated 100,000 people have already perished in the disaster but Oxfam warned this figure could multiply 15-fold.

Aid is continuing to trickle into the country, the Red Cross confirming that a total of 10 flights containing emergency supplies will have landed in the capital Rangoon by today.

Charity and disaster response organisations are finally starting to reach the far-flung stretches of the Irrawaddy delta in southern Burma, which bore the brunt of Cyclone Nargis more than a week ago.

Survivors are beginning to flood into towns after fleeing their shattered villages as they desperately look for food and water.

Britain's International Development Secretary Douglas Alexander confirmed yesterday that a British government assessment team had been allowed into the country.

And in a further move suggesting that the Burmese regime was becoming more open to foreign help, the Thai Foreign Minister Dr Noppadon Pattam announced he would meet his Burmese counterpart in Rangoon tomorrow to discuss getting more aid into the country.

But agencies say visa restrictions on specialist staff and long clearance times on aid flown into the country is impeding their efforts to save lives.

The UN estimates that two million people have been displaced by the cyclone with the majority left without shelter and clean water.

Large parts of the country's infrastructure have been shattered, bloated corpses and the rotting remains of cattle littering the countryside.

The huge storm surge left behind filthy pools of stagnant water, creating the perfect breeding conditions for mosquitos carrying malaria and dengue fever.

Oxfam's regional director for south-east Asia, Sarah Ireland, said: "With the likelihood of 100,000 or more killed in the cyclone there are all the factors for a public health catastrophe which could multiply that death toll by up to 15 times in the coming period.

"In the Boxing Day tsunami, 250,000 lost their lives in the first few hours but we did not see an outbreak of disease because the host governments and world mobilised a massive aid effort to prevent it happening.

"We have to do the same for the people of Burma."

Foreign Secretary Mr Miliband criticised Burma's response to the disaster. In a stinging attack he told BBC1's The Politics Show: "A natural disaster is turning into a humanitarian catastrophe of genuinely epic proportions in significant part because of the malign neglect of the regime.

"The basic point is that the scale of the response inside the country is so far inadequate to the scale of the disaster."

Despite the burgeoning crisis, the Burmese authorities yesterday pushed ahead with a referendum, a decision Mr Miliband branded "bizarre"

The umbrella Disasters Emergency Committee said donations of around £5m had now been made to an appeal fund.


Disaster committee calls for gifts

People are being urged to give to an appeal fund to help to save the lives of those affected by the Burmese cyclone.

The Disaster Emergency Committee has raised more than £5m for those displaced by Cyclone Nargis.

But the growing size of the crisis has prompted the committee to say much more is needed.

The committee is an umbrella group for relief organisations trying to get aid to the people at risk.

Chief executive Brendan Gormley said: "Our DEC agencies and their partners are on the ground now helping thousands in desperate need of water, food and medical supplies."

He added: "We can't let these people down and we're relying on the generous support of the British public to help us continue this life saving work."

Donations to the appeal will be used for food, clean water, medicines and shelter.

A donation can be made online at www.dec.org.uk or by calling 0870 6060900.