I understand that an official request to leave the EU has to be put down by the UK under article 50 of the Lisbon Treaty. Until that moment, the UK will be considered as a full Member State.
My Department has been informed that this means that infrastructure projects involving EU co-funding under the Connecting Europe Facility for transport in the UK will proceed as normal for the time being.
My Department feeds into the Interdepartmental Committee on Brexit chaired by the Department of the Taoiseach and all risks associated with Brexit including infrastructure deficits that could arise for example out of lack of co-financing for cross-border projects including those co-funded by the EU are being continually evaluated as information comes to hand and as the Brexit process progresses.