Mr O’Callaghan called to the Bar in 1993 and to the Inner Bar in 2003. He served on Dublin City Council from 2009 until his election to the Dáil in 2016.

Helen McEntee, who led the Department of Justice from 2020, is now minister for education and youth.

James Browne, previously a minister of state in the Department of Justice, has been promoted to the Cabinet as minister for housing, local government and heritage.

Taoiseach Micheál Martin said: “Ensuring the safety of our communities, the ability to walk the streets or be in your own home without fear, is a fundamental responsibility of government. We need to improve the level and impact of community policing, and we need to address new forms of behaviour which are causing great damage.

“The Department of Justice will be significantly reformed in order to make sure that it is focused on our programme of action.”

He added: “In addition, we will address the fact that government activity on migration is too dispersed and requires more direct leadership.

“A new division of the Department of Justice will take responsibility for the control of our borders, the management of immigration and coordination of integration. This will be headed by a secretary general with a distinct budget and more direct oversight.”

Four ministers of state have been named by the government and Mr Martin said legislation would be introduced to allow “further deputies to serve as ministers of state covering an expanded range of responsibilities in order to fully address the priorities set out in the programme for government”.