Tánaiste Mary Coughlan will today carry out her first official duty in her new role when she represents the Government at the Order of Business in the Dáil.
The Donegal South West TD will be deputising for Taoiseach Brian Cowen who is in Belfast for a round of engagements including talks with British Prime Minister Gordon Brown.
The outgoing Minister for Agriculture will also be preparing herself for her new portfolio position in the Department of Enterprise, Trade and Employment.
A close ally of Mr Cowen, Ms Coughlan (43) had seconded his nomination for Fianna Fáil party leader last month.
Prior to yesterday's reshuffle, she had made clear that she wanted a move from Agriculture, where the mother of one found the high level of foreign travel was not conducive to family life.
She was Minister for Social and Family Affairs Minister in Bertie Ahern's first Government from 1997-2002.