Robert McCartney's sisters arrive in Washington today for meetings with senior American politicians.

Sinn Fein president Gerry Adams is also in town - but has been frozen out by the Bush administration.

Senator Edward Kennedy, one of Irish-America's most prominent leaders, has also pulled out of a meeting with Adams because of the IRA's "ongoing criminal activity and contempt for the rule of law".

It has also emerged that two female Sinn Fein election candidates, and Sean Hayes, a former councillor and one-time Westminster candidate, were in the bar on the night McCartney died.

Sinn Fein's chief negotiator, Martin McGuinness, appeared to warn the family not to get too heavily involved in party politics.

He said he supported the McCartney family but said they "would need to be very careful" that they "don't step over the party political line and allow themselves to be used or manipulated" by others opposed to Sinn Fein.