A major American investment trip to Northern Ireland is in jeopardy because of the new Stormont impasse over welfare reform, the US special envoy has warned.
Senator Gary Hart revealed the visit was "almost totally dependent" on the latest row over the benefits shake-up being resolved.
Back in Belfast yesterday, he said American business chiefs would want to know the likely rate of corporation tax - which is tied into the deal on welfare - before coming.
But Mr Hart, who reports on Northern Ireland to the Obama administration, said he was optimistic the stand-off over how the welfare reforms will work could be resolved in the next few weeks. He indicated he expects that agreement will be reached before the general election, now just six weeks away.
The US State Department has been organising the visit involving around a dozen senior chief executives from companies which could invest here. It has been pencilled in for "late spring".
Asked if he was sending Stormont a warning, Mr Hart insisted: "I wouldn't do that, it's not my position to do it, but it's commonsensical, everybody knows this.
"For example, the issue of the corporate tax rate is intricately related to the issue of the resolution of the budget, which is dependant on the resolution of the so-called welfare reforms, so these are dominoes which all fall together.
"I'd put it this way - if there is no clear number on the tax rate for corporations, I would think it would be difficult, if not impossible, to get any company to come here.
"The first question the international vice-president is going to ask is 'how much tax to we have to pay?' And if the answer is 'we don't know' they'll say 'when you know, tell me and we'll look into it'." Speaking at the American consulate, he revealed he held separate meetings with First Minister Peter Robinson and Deputy First Minister Martin McGuinness on Wednesday.
And he said it was DUP leader Mr Robinson who deserved the credit for suggesting that last week's expected round of St Patrick's week meetings in the White House in Washington was "postponed" rather than cancelled.
At one stage, Sinn Fein president Gerry Adams described organisation at the White House as "bizarre" but said if meetings were cancelled it was no skin off his nose.