Sinn Fein is being accused of burying its head in the sand in relation to allegations that ratification of the Nice Treaty will lead to a flood of foreign workers.
Minister of State for European Affairs, Dick Roche, says the party is showing no principle by refusing to make known its position on these false allegations.
It follows concerns that the "No to Nice" campaign is making alarmist statements on immigration that could stir up hostile attitudes to migrant workers here.
Minister Roche says he is surprised that Sinn Fein has failed to publicly distance itself from these remarks.
"I am absolutely amazed that a party like Sinn Fein, unlike other parties to the left, has failed to come out and distance itself from the zenophobia which is being put around by Anthony Coughlan of the National platform and Justin Barrett of the "No to Nice" campaign in the last few days."