LONDON (Reuters) - The heads of Northern Ireland’s devolved government have written to the European Commission, asking for potential problems with the Northern Ireland Protocol agreed between the EU and the UK to be resolved urgently, RTE’s Europe editor reported on Monday. In their letter, the leaders of the DUP and Sinn Fein parties described as “unacceptable” an alleged threat to the continuity of existing food supplies to Northern Ireland’s supermarkets once the protocol takes effect, the Irish broadcaster’s Tony Connelly reported. He said the two leaders said that some of the issues would be made simpler by the conclusion of a Free Trade Agreement between Britain and the EU, “but urgent action to resolve the issues in the Protocol need not and should not be dependent on that process”.