Bermuda, the Caymans and the Isle of Man have all been lumped in with a list of other jurisdictions which "allow companies to set up a PO Box number and claim they operate fully there".

A press statement by the US Treasury this week singled out Ireland as one of the countries that its new revenue campaign was focused on, with Congressman Richard Neal saying he was unhappy Ireland was on the list and that it had a definite tax system, according to Dublin-based newspaper The Herald.

"Ireland should not have been on that list," he said, before pointing out the significance of the fact that US President Barack Obama did not mention Ireland at his press conference about tightening up tax rules, the report said.

Rep. Neal, who added that President Obama would soon visit Ireland, has tabled legislation that would have punitive tax implications for non-US insurance groups, including those in Bermuda.

Asked whether Ireland could rely on him to lobby the US government, Rep. Neal was hesitant, according to the paper, but did indicate that he was not keen to see all of these companies being forced back into the States. "That's a pretty heavy lift" he said. "The idea is to keep American companies competitive in a global economic environment."

The congressman said he felt the relationship between the nations is "one of the most important bilateral relationships in the world".