For Lewis Sida, a tough day at the office means decisions that could make the difference between life and death for thousands.

The latest crisis to fall into the "in" tray of Save The Children's emergencies director is the humanitarian disaster in Liberia.

After a bloody 14-year war and the ousting of warlord-turned-president Charles Taylor, there are the first signs of lasting peace.

That has come at a price. There are 250,000 displaced people struggling to survive on the streets of the capital Monrovia.

An estimated one million people are trapped in appalling conditions in other towns or cut off from help in the countryside.

Lewis, who lives in Talbot Terrace, Lewes, said: "Right now it is the most serious humanitarian crisis in the world."

During the years of on-off fighting, it is estimated 200,000 Liberians have died. Another 1.5 million have been forced to flee homes.

The hundreds of thousands now crammed into the streets of Monrovia have no shelter, food or clean water.

Lewis said: "Monrovia is still a dangerous place to be. There is gunfire every night. There are bombs and bullets flying around as well as rapes, mutilation and murder.

"By day there is no running water and no electricity. They are living outside on the streets in monsoon conditions."

Save The Children is part of the Disasters Emergency Committee (DEC) Liberia Crisis Appeal, a joint effort by 11 UK charities to provide immediate aid.

The children's charity has already sent three planes carrying 40 tonnes of urgently-needed food and medical supplies to Liberia.

Even with all the aid agencies working together, they are unable to reach people trapped in cities outside Monrovia.

Although he masterminds the charity's response from London, Lewis has twice been to Monrovia.

He said: "I'm amazed by people's ability to get on with their lives, despite the desperate situation."

He said more than anything, it was money that was desperately needed now.

He said: "We have flown out cholera kits, high energy biscuits, emergency health kits, heavy plastic sheeting for emergency shelter, 10,000 collapsible jerry cans and water purification tablets.

"But we need to fund a rapid expansion of that work."

As well as malnutrition and dehydration, the refugees are at risk of dying from easily-

preventable illnesses like diarrhoea, cholera and measles and increasingly sexual abuse or exploitation.

Children are also being recruited into armed groups.

For more than a decade, Liberians have fought to survive as war has raged around them.

President Taylor agreed to step down on August 11 and took up an offer of asylum from Nigeria. West African peacekeeping troops moved in, opening the way for the aid agencies to step up their work.

Last week, the coalition of charities launched its appeal fronted by former EastEnders star Ross Kemp.

Lewis, 34, became involved in aid work when he went backpacking in Africa after university. He has survived war zones, earthquakes and bombings.

As much as he loves his work, he is always glad to return to Lewes.

He said: "When I come home I'm reminded of all that's good in the world. We are so lucky to live in this country, where it is safe and peaceful and people have a good standard of living."

Lewis is responsible for managing the work of the 63-strong team distributing aid.

As well as bringing food and water, the charity's workers carry out immunisations, run a primary health care centre and try to reunite children separated from their families.

Lewis said with the help of the British public, the charity coalition would continue to fly in desperately-needed supplies.

He said: "We need money because although there is aid getting through, it is needed on a huge scale."

Brendan Gormley, chief executive of DEC said: "The appalling conditions caused by the climax of the bloody civil war in Liberia will lead to widespread deaths without an urgent increase in the aid effort. Immediate financial help from the public can ensure the DEC agencies will be able to step up their vital work quickly."

Donations to the Liberia Crisis Appeal can be made on 0870 60 60 900 or by the web site www.DEC.org.uk Money can also be handed in at post offices and branches of most banks.

The other DEC charities involved in the Liberia Crisis Appeal are Actionaid, British Red Cross, Cafod, Care International UK, Christian Aid, Concern, Merlin, Oxfam, Tearfund and World Vision.