* Trial was due to start Weds, prosecutors want more time
* Kenyatta's lawyers hope case will be thrown out
* Case, crucial to ICC, divides African, Western countries
By Thomas Escritt
AMSTERDAM, Feb 5 (Reuters) - The fate of the politically fraught trial of Kenyan President Uhuru Kenyatta could be decided on Wednesday, when prosecutors at the International Criminal Court plead for more time.
Kenyatta's lawyers hope the case will be thrown out, putting an end to a trial that has driven a wedge between African countries - which criticise the ICC for targeting their continent - and the court's Western backers.
The Kenyatta trial is crucial to the ICC, which has secured only one conviction and suffered a string of collapsed cases since it was set up 11 years ago. Kenya says the court risks destabilising east Africa if it presses on with the charges.
Western countries, while keen to back the ICC, are also anxious to maintain relations with Kenya, seen as a key ally in the battle against militant Islamism in neighbouring Somalia.
Kenyatta is charged with crimes against humanity during the violence that swept Kenya six years ago, when 1,200 died and thousands were driven from their homes. He denies the charges.
ICC prosecutors say he orchestrated the clashes, but their case has been weakened by the withdrawal of a string of witnesses since charges were first brought four years ago.
The trial had been due to start on Wednesday, but was postponed for a fourth time last month when prosecutors said another witness had withdrawn, and requested more time to gather evidence.
Prosecutors say their witnesses have been blackmailed or intimidated into withdrawing.
In a Jan. 31 court filing, prosecutors said a "climate of fear" had weakened their case against Kenyatta, and said judges should rule that Kenya was in breach of its obligation to help the court's investigators.
"Several individuals with information relevant to the case refused to agree to be included on the prosecution's witness list due to fears that they or their family members would be targeted," prosecutors said in the filing.
The case has grown only more controversial throughout Africa since Kenyatta, the son of his country's founder, won a presidential election last year on a joint ticket with William Ruto, his deputy, who is on trial on similar but separate charges.
Following his victory, Kenyatta used his position as leader of East Africa's economic powerhouse to rally African Union allies in a diplomatic push to have the United Nations Security Council defer the case against him.
Although that bid was unsuccessful, the ICC's 122 member states did agree to change court rules to make it easier for heads of state facing charges to give evidence by video link.
Prosecutors say authorities have obstructed attempts to interview police officers, and have given investigators only limited access to phone records crucial to building their case.
"Kenyatta's statements in which he accused the court of being 'the toy of declining imperial powers' engaged in 'bias and race-hunting' and the (Kenyan government's) multi-faceted campaign to derail the ICC process on the diplomatic front suggest a lack of willingness to co-operate," they wrote.
But Kenyatta's lawyers dismissed the prosecution request for extra time, labelling it a "last-ditch attempt ... to obtain fresh evidence in a failed case," and said judges should throw out the charges against their client. (Editing by Robin Pomeroy)