Libya will challenge any compensation demands from relatives of IRA victims who say the terror group used explosives supplied by Tripoli.Britain’s Gordon Brown now insists he will back the families’ claims but a son of Colonel Gaddafi says they will be resisted in court. Over the release of the Lockerbie bomber, Saif al-Islam Gaddafi said Brown was not involved but that the case was being politicised. “Come on, it is a tragedy. It is immoral. It is completely immoral to use this case to advance your own political agenda and this is what happened in the UK and in London in particular,” he told a British TV channel. “There are political parties fighting each other, preparing themselves for the next election and they are trying to use this tragedy for their agenda. They are disgusting.” The British Prime Minister has been embroiled in controversy over Lockerbie. He has firmly denied claims that business interests were involved in the decision to free terminally-ill Abdel Basset al-Megrahi. Released last month on compassionate grounds by Scottish authorities, he was given a rapturous reception when he arrived back in Libya, in scenes that caused widespread outrage.