In 1986 he took up the position of advisor to the Minister of State at the Department of Fisheries, Forestry and Tourism, Michael Moynihan, resigning from the agricultural consultancy to do so.

On 9 March 2011, he was appointed as Minister of State at the Department of Environment, Community and Local Government with special responsibility for Housing and Planning, attending meetings of the cabinet.

[7][8][9] On 15 November 2011, he resigned as Minister of State due to his opposition to the government's decision to close Columb Barracks in Mullingar.

[10][11] Penrose said: "I understand and appreciate that significant efforts were made by my Labour colleagues in government, who fully understood the depths of my feelings in this regard, to resolve this matter, but to no avail.

[2] In February 2012, The Phoenix magazine contrasted Penrose who "eats at the PLP tables in the Dáil restaurant and is often seen chatting to Gilmore on the corridors" with two other backbenchers who lost the party whip, Tommy Broughan and Patrick Nulty, both of whom had been "banished" from the Labour parliamentary offices.