Alderdice was the leader of the Alliance Party of Northern Ireland from 1987 to 1998, and since 1996 has sat in the House of Lords as a Liberal Democrat.

He was educated at Ballymena Academy and the Queen's University Belfast (QUB) where he studied medicine and qualified in 1978.

[2] He worked part-time as a consultant psychiatrist in psychotherapy in the NHS from 1988 until he retired from psychiatric practice in 2010.

[3] Alderdice claims a distant relationship to John King, a 19th-century Australian explorer and the sole survivor of the Burke and Wills expedition.

[3] Alderdice was willing to talk with Sinn Féin after the IRA called a ceasefire in 1994, when many in the unionist community regarded such discussions as unacceptable.

Mo Mowlam said that Alderdice's "political and parliamentary experience mean that he is well suited to carry out this role".