And that very visit could be in jeopardy if the specific Adams fundraising component is denied by the U.S. government.

Seven members of the House of Representatives have signed on to a statement in which they say they "strongly oppose efforts to ban Sinn Fein fundraising in the United States."

The signatories include the Republican chairman of the Friends of Ireland group in Congress, Rep. James Walsh, and Rep. Richie Neal, a Democratic co-chair of the Ad Hoc Committee on Irish Affairs.

The group plays up its bipartisan composition in a statement in which they express "in the strongest possible terms our opposition to any effort that would prohibit Sinn Fein from raising funds."

"We urge the U.S. Department of State to lift the fundraising ban immediately. It is our belief that this decision is unwarranted, and may have a negative and unintended impact on the progress that has been made in the Northern Ireland peace process," the congressmen state while pointing to an "extraordinary sequence of recent events" has helped move that process significantly forward.

The signatories pointed to the International Monitoring Commission published eport "which characterized the IRA's transition to exclusively peaceful and democratic means as 'encouraging.'"

And they highlighted the British government's decision to lift financial sanctions it had imposed on Sinn Fein.

"The U.S. Department of State should follow suit," the statement said.

"We believe that the Sinn Fein leadership has kept its word and honored its commitments. At this critical moment in the peace process, they should not be penalized for delivering on their promises," it added.

"Every political party from Northern Ireland has the right to fundraise in the United States. We are simply calling for a level playing field. The ban that prevents Sinn Fein from fundraising in the United States should be lifted promptly."

In addition to Walsh and Neal, the statement was also signed by reps. Joe Crowley, John Sweeney, Eliot Engel, Frank Pallone and Brian Higgins.

Adams is due to be the keynote speaker at a Friends of Sinn Féin fundraising dinner at the Sheraton Hotel in Manhattan on Thursday, Nov. 10.

The dinner is an annual event but this year's is a special gathering given that it coincides with the 100th anniversary of the founding of Sinn Féin.

FOSF president Larry Downes said that the dinner was going ahead and would be a fundraiser even if Adams was prevented from attending.

Downes said that Adams had applied for a visa with a fundraising element but acknowledged the possibility that if Adams did not get the desired fundraising component he "may not come to the country at all."

Downes described the current ban on fundraising - which was applied to the party's chief negotiator Martin McGuinness during his recent U.S. visit - as "unfortunate."

He said he could not understand why "anybody would be doing this at this time."

"People should be supporting Adams, not undermining him," Downes said.

While there appears to be problems with the precise nature of an upcoming Adams visa - specifically whether or not it will be broad enough to allow Adams to personally engage in fundraising - Friends of Sinn Féin is not in any way restricted in its fundraising operations in the U.S.

It can do so year round with or without the presence of leading party figures. The group reports the gross amounts of money it has raised to the U.S. Justice Department on a six monthly basis.