AMSTERDAM (Reuters) - Lawyers for Kenyan President Uhuru Kenyatta asked on Thursday for his trial on charges of crimes against humanity to be abandoned, saying defense witnesses had been intimidated.

Kenyatta and his deputy William Ruto have been accused orchestrating a wave of violence that swept Kenya after contested elections in 2007, costing 1,200 lives. Both deny the charges made against them at the International Criminal Court.

"The defense is in possession of substantial evidence of a serious, sustained and wide-ranging abuse on the process of the court," Kenyatta's lawyers said in a 38-page filing, which contained extensive but largely redacted transcripts from telephone conversations.

They called for a "permanent stay of proceedings", saying a prosecution witness, who had also helped prosecutors gather evidence and locate further witnesses, was involved in a bid to intimidate unnamed individuals.

Prosecution lawyers have also said their witnesses have been intimidated.

Kenya has called for the cases to be dropped or moved closer to home. It has also rallied African support against the ICC, which has until now charged only Africans.

Ruto went on trial at the Hague-based court last month and Kenyatta's trial is due to start on November 12.

(Reporting By Thomas Escritt; Editing by Andrew Heavens)