Former prime minister Tony Blair has been asked to give evidence to a parliamentary committee looking into the failure to include UK victims of IRA violence in a compensation deal with Libya's Colonel Muammar Gaddafi.

Lawyers for victims of attacks using Semtex explosives supplied by Gaddafi - who was killed in 2011 - said that Mr Blair had "questions to answer" about why they were locked out of a the 2008 deal which saw Libya pay around £1 billion in compensation to US victims of terrorism.

The deal provided Gaddafi's regime with immunity from terrorism-related law suits, effectively invalidating the claims of British victims who were suing Libya in the US courts.

The House of Commons Northern Ireland Committee, which is conducting an inquiry into the compensation issue, has been handed a copy of an email sent to Mr Blair's office by ex-ambassador Sir Vincent Fean in 2008, a few days before the former PM met Gaddafi in Libya.

The victims' lawyer Jason McCue told the committee last month that the message made it "very clear that Tony Blair is working with President (George) Bush and Gaddafi to bring out what is known as the Libya claims settlement agreement, which deprived all the British citizens of compensation".

In a letter to the former PM, committee chairman Laurence Robertson told Mr Blair: "There is a real sense amongst the victims that an opportunity to include them in the agreement reached between the US and Libya was missed in 2008. The committee is keen to shed some light on this and in so doing maybe provide some kind of closure for the victims.

"As you are no doubt aware, there has been a lot of concern voiced as to the nature of any involvement you may have had in negotiations between Libya and the US in the run-up to the signing of the US-Libya claims settlement agreement, which precluded the provision of compensation for the UK victims."

Mr Robertson asked Mr Blair to submit written evidence to the inquiry by October 23, and said that he could later be called to appear before the cross-party committee to answer questions in person. Sir Vincent is due to give oral evidence to the inquiry on October 14.

Mr McCue said the call for the ex-PM to give evidence was a "great step forward", and could help clear up the question of whether the victims' rights were sacrificed for business deals.

"The United States, as well as Germany and France, all managed to secure their business interests without relinquishing responsibility and respect for their own citizen victims," said Mr McCue.

"Government departments ever since have be unable to explain why it is that the UK's victims of the IRA have been prevented from gaining compensation, as other countries have, from Libya.

"The lives of the UK victims and their families seem to have been sacrificed for the benefit of half a billion pounds' worth of celebrated business deals that never fully transpired. Mr Blair's answers may be the key to revealing finally how this failure of duty of care transpired during his government, and successive British governments."