The power of the government to prevent the president leaving the country is enshrined in Article 12.9 of the Irish constitution, which states that "the President shall not leave the State [...] save with the consent of the Government". Moreover, though Articles 13.7.1 and 13.7.2 permit the president to address either house of the Oireachtas on any matter of national or public importance, and further to "address a message to the Nation at any time and on any such matter", Article 13.7.3 qualifies that provision by stating that "every such message or address must, however, have received the approval of the Government".
Brady 1988, p. 154. Brady, Anna (1988). "814". Women in Ireland: An Annotated Bibliography. Westport, Connecticut: Greenwood Press. ISBN0-313-24486-3. ISSN0742-6941.