A political settlement in Northern Ireland will not help the campaign to bring Robert McCartney 's killers to justice, his family claimed tonight.
The five McCartney sisters, who insist the IRA are involved in a sinister cover-up of the murder, warned that violence in Belfast would not end if a deal was struck.
The family was given an unprecedented welcome by leading US politicians in Washington as they vowed to make it known that such brutal violence will no longer be tolerated.
"Even if there is a peace deal, this thing is not going to end," Catherine McCartney warned.
"There will still be people walking through the streets of Ireland able to kill, and if these people are brought to account it will be a sign that law and order prevails and not men of violence."
The five McCartney sisters and Mr McCartney 's fiancee Bridgeen Hagans were given strong support by US Envoy to Northern Ireland Mitchell Reiss and leading senators, including Ted Kennedy and Hillary Clinton.
Senator Kennedy, who refused to meet Sinn Fein leader Gerry Adams amid the growing outrage surrounding the attack, warned that the peace process could only be built on trust and confidence.
"Sinn Fein cannot be a fully functioning democratic party with the albatross of the IRA around its neck," he warned.
"I believe Mr Adams wants to see the IRA disbanded but there is a time to hold 'em and a time to fold 'em and we are long overdue."
The senator said robbery and murder were despicable acts of criminality and said he deplored the current setbacks in the peace process.
The growing backlash against Sinn Fein showed no sign of abating as leading politicians stepped up to support the McCartney family.
Northern Ireland Secretary Paul Murphy told the sisters that in 10 years of travelling to Washington he had never seen such an overwhelming upsurge of support.
"I think that, no matter what, the least that is happening is that this message is getting through.
"If this continues you may actually be able to change the face of politics in Northern Ireland," Mr Murphy said.
Republican senator and former presidential candidate John McCain expressed hope that the "outrageous" murder may at least bring a peace settlement.
"We say to anyone who has any ideas that the McCartney family are not doing the right thing and who is discouraging them from doing so: 'Just don't'," he said.
The family has dismissed warnings from Sinn Fein's Martin McGuiness that they risk losing support by stepping over party political lines. Catherine said they would not be manipulated by any politician and were entirely motivated by their brother's death.
President George Bush said he was looking forward to meeting the McCartney family tomorrow, stressing the importance for all parties in Northern Ireland to denounce violence.
Senator Clinton said that, as Good Friday approached, it would be fitting that anyone with any involvement in Mr McCartney 's murder should honour the 1998 accord and bring his killers to justice.
Agencies