Adams protest at visa conditions

In March, Mr Adams was denied a meeting with President Bush

Sinn Fein's Gerry Adams will call off a visit to the United States if he is banned from addressing fund-raising events, a party MP has said.

The dispute appears to centre on whether the visa will allow fund-raising by the party president.

He is due to meet US officials in Belfast to discuss a potential ban, which Martin McGuinness said would be "ludicrous and unsustainable".

Sinn Fein said a fund-raising ban would bolster anti-Agreement unionism.

The party has insisted the US administration should recognise the reported completion of IRA decommissioning and its July statement announcing an end to its armed campaign.

In March, Mr Adams was denied a meeting with President Bush at the White House and Senator Ted Kennedy cancelled a meeting with him because of the IRA's "ongoing criminal activity".

Mr McGuinness said: "These fundraising events allow supporters of Irish unity to contribute to Sinn Fein's political programme to achieve this through peaceful and democratic activity.

"Such support is entirely legitimate and indeed necessary in demonstrating that politics works.

"The US has played a pivotal role in the creation and evolution of the peace process."