DUP leader Ian Paisley is due to give evidence to the Bloody Sunday Inquiry in Derry later today.
Lawyers for the inquiry are expected to ask the hardline unionist what, if anything, he was told prior to the British army operation against a Catholic civil rights march which left 13 civilians dead in January 1972.
Mr Paisley had organised a counter-demonstration in Derry on the day of the civil rights march, but he suddenly called it off ahead of the shootings by British paratroopers.