Gordon Brown and a senior American envoy today pushed Kenyan leaders to end the unprecedented wave of political violence which has left more than 360 dead and up to 250,000 people homeless.

Amid growing international pressure, there appeared to be some progress in moving towards an agreement between President Mwai Kibaki and the opposition leader Raila Odinga on how to resolve last month’s disputed elections.

Meanwhile, aid groups said supplies of food and clean water were running dangerously low in some areas and that there was a health emergency in the makeshift camps set up to receive the homeless.

Mr Brown today denounced the violence as “completely unacceptable” and said he believed Mr Kibaki and Mr Odinga, the leader of the Orange Democratic Movement, were ready to take the steps needed to bring it to a halt.

“It is very important that the two sides come together,” said the Prime Minister. “We have been working night and day behind the scenes to see what we can do to bring the sides together.”

“I think Mr Odinga and Mr Kibaki both recognise that unless they make a change, unless something happens that brings them together, the prospects for Kenya are very poor indeed.”

Mr Brown said he expected talks under international mediation to cover the issue not only of whether the poll should be re-run, but whether Kenya’s constitution should be re-written to create a post of prime minister as a counterweight to the president.

“These talks should take place urgently,” he said. “Loss of life is completely unacceptable. This is a country that needs a democratic path and a path of economic and social justice.”

Mr Odinga told the BBC he was willing to incorporate Mr Kibaki in government in a bid to resolve the crisis. He suggested the president be allowed to retain his role under his old mandate from elections in 2002 while talks take place, and that he was prepared to co-operate with him in a future government.

The opposition leader said he expected President John Kufuor of Ghana, the current head of the African Union, to arrive in Nairobi within the next two days to act as a mediator for talks between the rival camps.

“The crisis is very grave and because of this we are willing to walk the extra mile to find a solution,” said Mr Odinga. “We are willing to sit down with Mr Kibaki in the presence of an internationally recognised mediator so we can put our terms on the table.

“In order to resolve the crisis, we are willing to talk. I am willing even to co-operate with Mr Kibaki in the government.”

Jendayi Frazer, US Assistant Secretary of State for African Affairs, shuttled between both camps in a bid to unblock the stalemate with Desmond Tutu, the South African Nobel peace laureate, also taking part in the negotiations.

After meeting Mr Frazer on Saturday, Mr Kibaki said a unity government “would not only unite Kenyans but would also help in the healing and reconciliation process”.

No food has moved in Kenya since unrest broke out. However, a convoy of 20 food trucks left the port of Mombasa today bound for Nairobi and Eldoret, where many of the people displaced by the violence are gathered.

Wubeshet Woldermariam, country director of the British charity Merlin, said: “If peace isn't restored within the next few days, disease outbreaks and severe dehydration are very real threats.”

Thousands of British tourists remain in hotels with dwindling supplies on the Indian Ocean coast north and south of Mombasa. Kenya’s second city was the scene of further rioting on Saturday and another clashes are expected at a rally called by opposition MPs for tomorrow. A nationwide demonstration has been called for Tuesday.

Adam Wood, the UK High Commissioner to Kenya, said today that the situation appeared calmer, although violent incidents were still being reported in slums and in the west of the country. The Foreign Office is advising against all but essential travel to Kenya,

The High Commission in Nairobi will reopen to the public on Monday with services limited to emergency applications for passports and capsular assistance in case of death, arrest or hospitalisation

David Miliband, Foreign Secretary, will update MPs on the situation tomorrow when he gives a statement to the House of Commons.

Despite a lull in fighting today the United Nations said it would take time to restore stability in regions where clashes had been severe, amid reports of continuing but more isolated acts of violence. The crisis has had an impact beyond Kenya's borders, with fuel shortages disrupting transport and trade in Uganda, southern Sudan, Rwanda and the eastern Democratic Republic of Congo.

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