Peter attended Bangor Grammar School and graduated from The Queen's University of Belfast in Law and Accountancy. He was called to the Bar of Northern Ireland in 1992 and is a former editor of The Ulster Review. Peter has also been a member of the Queen's University Senate since 1996 and is also leading member of the University Convocation. He was elected to the Northern Ireland Peace Forum in 1996 for the constituency of North Down.
Peter was first elected as a Councillor in 2005 to represent the people of Ballyholme and Groomsport. Peter served as a DUP MLA from 2002 until 2022 during which time he also served as Minister of Education on two occasions.
Peter was appointed to the House of Lords in 2002 as Lord Weir of Ballyholme.