The Northern Ireland Affairs Committee of MPs came under fire on Sunday night – from one of its own members.
SDLP leader Alasdair McDonnell voiced anger over its recommendation that Secretary of State Theresa Villiers "close the current loophole" allowing overseas donations to parties in Northern Ireland to be made via the Irish Republic.
Calling on Mrs Villiers to uphold the right of Irish citizens to support political parties across the island of Ireland, Dr McDonnell said: "This recommendation undermines the spirit of the Good Friday Agreement. The SDLP in its evidence to the committee on this Bill made this point.
"For the committee to take this stance and treat political donations within the island of Ireland as foreign is unacceptable and deeply offensive to every Irish citizen."
But the move was welcomed by Ulster Unionist leader Mike Nesbitt who said: "Sinn Fein have benefited unfairly from this for too long."
Green Party leader Steven Agnew said: "I now hope that the Government will accept the committee's recommendation as voters deserve a clear picture of who is funding our political parties."