The DUP, the Ulster Unionist Party and the SDLP have reacted with annoyance and frustration to indications that the US administration may cancel the usual annual St Patrick's Day White House reception in order to avoid any embarrassment over Sinn Féin's presence at the event.
The parties complained that they were likely to be "punished" by being excluded from the White House because of the alleged £26.5 million IRA robbery of the Northern Bank.
US sources said that no formal decision had yet been taken on the event, although it is understood that President Bush's annual reception will be cancelled for two linked reasons: to make a point to Sinn Féin about the robbery but also to avoid any suggestion of Sinn Féin being politically isolated.
A State Department spokeswoman said that the issuing of invitations was still under review. "No decision has been taken regarding invites being sent to Northern Ireland parties," she said. "The issue is still under consideration."
The SDLP, Sinn Féin, and the Ulster Unionists nonetheless plan to travel to Washington for events on and around March 17th, including the lobbying of senators, Congress members, business leaders and others in positions of influence.
However, the DUP's deputy leader, Mr Peter Robinson, indicated that the DUP presence on Capitol Hill this year could not be guaranteed considering the attitude of the US administration.
"This is typical of the way governments face up to these problems. Rather than deal with the republican movement, they want to punish everybody. It is outrageous that everybody should be tarred with the same brush," he said.
The SDLP deputy leader, Dr Alisdair McDonnell, said that US goodwill towards the peace process was "being recklessly squandered" as a result of the alleged IRA raid.
Dr McDonnell said that the SDLP had spearheaded efforts to generate US support for the peace process, but that was now in danger of being wasted as a result of reaction to the robbery.
"The US administration is clearly annoyed at the IRA raid of the Northern Bank - and at Sinn Féin's failure to face up to the huge damage done by it. The failure of the talks between the DUP and Sinn Féin has been damaging too," he added.
UUP Assembly member Sir Reg Empey added: "Instead of having the determination to ban Sinn Féin, they (the US administration) have banned everyone else. This sends out a bad signal. One hopes that Prime Minister Tony Blair won't follow suit, but will instead back democrats rather than those engaged in criminal activity and paramilitarism."
A Sinn Féin spokesman said that whoever attended the White House reception was a matter for the US administration. So far, he was unaware of any official decision on the matter.