A sister of Northern Ireland murder victim Robert McCartney tonight demanded Tony Blair ask Sinn Fein leaders about their members 'lack of co-operation' with an inquiry.
The Prime Minister should ask them "very serious questions" about party members' reluctance to co-operate with the inquiry into the murder said Catherine McCartney.
She was speaking after meeting the Prime Minister in Downing Street.
She was accompanied by sister Paula and Sinead Commander, whose husband, Jeff, was assaulted during a confrontation between pro- and anti-McCartney factions.
The campaign to find the killers of the Belfast father-of-two has upset some in the republican Short Strand area.
His family insist it is a misconception to blame rogue republican elements for the killing of Mr McCartney following a row in a bar.
Evidence points towards the involvement of those now applying for prominent roles in community organisations which stem from benefits of the peace process, they say.
Speaking after her meeting in No 10, Catherine McCartney said the family needed answers rather than sympathy.
"For members of a political party to not co-operate in a murder investigation, I just won't accept that that should be tolerated by anybody," she said.
Ms McCartney told reporters: "What we want is very simple and we should not have to lead this campaign.
"It is a disgrace that we are having to stand here outside Downing Street and seek justice for my brother.
"What we want is people to come forward with the evidence they have so the people involved in my brother's murder can be brought to justice."
Mr McCartney was stabbed outside a bar in January during a confrontation between republicans who had returned from a Bloody Sunday march and his friend, Brendan Devine.
His friend survived the knife attack.
The McCartney sisters and his partner, Bridgeen Hagans, have accused republicans of cleaning up the murder scene and forcing witnesses to remain silent since his murder.
Their campaign forced the IRA to expel three of its members.
Two men were also charged in connection with the murder in June.
The family has met US President George Bush this year in the White House, as well as a number of senior politicians in Washington such as Senator Hillary Clinton and Edward Kennedy.