Omagh bomb victims were today launching a major drive to raise £1m to finance a civil action against the men suspected of the atrocity.
They have five months to find the cash to begin the unprecedented legal proceedings.
Mr Victor Barker, whose son James was among the 29 people killed in the August 1998 outrage, said that families must act now.
He said: "We are not giving up on the criminal investigation, but we need to do all we can to assist ourselves, we can't just rely on others all the time."
Ex-Northern Ireland Secretaries Mr Peter Mandelson and Sir Patrick Mayhew were expected to join relatives and MPs at the House of Commons to support the legal bid.
So far around £150,000 has been raised, but Mr Barker is confident that the remaining money can be found before the three-year limitation period for personal injury claims expires in August.
Only one man has been charged in connection with the Real IRA bombing.
Mr Barker is optimistic that a civil action could unearth new evidence needed to secure further prosecutions.
PA