Speaking to the media at Abhayarama in Colombo, MP Dullas Alahapperuma said the UNP was afraid that it would be unable to control the people once the Geneva report is released.
He quoted former Norwegian peace envoy Erik Solheim as having said that the report has found 40 Sri Lankans guilty.
Solheim says that he has been told by the UN human rights chief that those names would come as a surprise, said the MP.
It is claimed the list contains civilians, whose identities could be presumed, according to him.
When the BBC questioned him about the connection between the UN report and the general election, Alahapperuma said war heroes would never be betrayed.