LONDON (Reuters) - Significant gaps still remain between parties attempting to restore Northern Ireland s power-sharing administration, British Prime Minister Theresa May s office said on Monday after she  spoke with Irish counterpart Leo Varadkar. May and Varadkar agreed in a phonecall that it was in the interests of everyone that the executive was restored, but differences remained over issues such as the Irish language. Northern Ireland has been without a devolved administration since its collapse in January, raising the prospect of direct rule being re-imposed from London. 