Kenya's opposition has re-arranged a banned mass rally of thousands of supporters in Nairobi, 24 hours after it was originally scheduled.

There have been running battles between police and opposition supporters since an election last week and the rally had been originally postponed until January 8 in an attempt to end violence.

But opposition spokesman Salim Leone said: "The rally is on for tomorrow."

Anger over the December 27 polls triggered violence which has left over 300 people dead, including dozens of terrified women and children who died when the church in which they were sheltering was torched.

More than 100,000 people have been forced from their homes and Britons are being told to cancel any non-essential visits to the country by the Foreign Office.

And all of the UK's major tour operators have suspended holidays to Kenya for the next two days, the Federation of Tour Operators has said.

The violence in the capital has been repeated in other towns, including the opposition stronghold of Kisumu in west Kenya.

But President Mwai Kibaki has offered to talk to political rivals when the violence subsides.

He said: "I am ready to have dialogue with the concerned parties once the nation is calm.

"I am deeply disturbed by the senseless violence instigated by some leaders. Those who continue to violate the law will face its full force."

World leaders have strongly condemned the recent wave of political and ethnic violence and urged a return to peace.

Prime Minister Gordon Brown was joined by United Nations Secretary General Ban Ki Moon as well as the United States in calling for an immediate end to violence.

"I believe there is a responsibility on the part of all the opposition and government leaders in Kenya to call on the supporters to end the violence that is taking place," he said.

US Secretary of State Condoleezza Rice made a personal appeal to Kenya's political rivals to forge a compromise.

South Africa's Nobel peace laureate, Archbishop Desmond Tutu, is in Kenya to try and start mediation.

He said: "This is a country that has been held up as a model of stability. This picture has been shattered.

"I don't think there is anybody who would be unmoved by the pictures that are coming out - of people who burned to death in a church. This is not the Kenya that we know."

Before meeting Archbishop Tutu, Mr Odinga called President Kibaki a "thief" who had carried out "a civilian coup".

He said: "The people will not take this vote-rigging by the government lying down."

The government has said "well-organised acts of genocide and ethnic cleansing were well planned, financed and rehearsed" by Mr Odinga's Orange Democratic Movement ahead of last week's vote.

Kenyan media has united in pleas for peace, with every major newspaper running the same front-page headline: "Save Our Beloved Country".

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