LAGOS, Sept 25 (Reuters) - A senior member of Nigeria's ruling party said on Friday corruption charges against him were politically motivated and pledged to back President Umaru Yar'Adua for a second term should he stand in 2011 elections.

Former Delta state governor James Ibori, a member of the Elders' Committee of the ruling People's Democratic Party (PDP), was instrumental in Yar'Adua's rise to power in 2007 and is one of Nigeria's most influential and controversial politicians.

He is among several former state governors to have been charged by Nigeria's Economic and Financial Crimes Commission (EFCC), and several of his associates are facing money laundering charges in the United Kingdom.

"We believe that all of the charges bought in the UK and in Nigeria are politically motivated and are driven essentially by Nigerian politics," Ibori told Reuters in an interview.

"What really concerns me is the fact that the UK court seems to have been used ... by disgruntled political office holders to settle scores at home," he said.