A unitary state is a state governed as one single unit in which the central government is supreme and any administrative divisions (subnational units) exercise only powers that their central government chooses to delegate. The great majority of states in the world have a unitary system of government.

Unitary states are contrasted with federal states (federations):

Devolution (like federation) may be symmetrical, with all subnational units having the same powers and status, or asymmetric, with regions varying in their powers and status.

Maurice Donald Williamson (born 6 March 1951) is a New Zealand politician, representing Pakuranga in the House of Representatives as a member of the National Party. He holds several ministerial portfolios outside the Cabinet: Building and Construction, Customs, Statistics and Land Information .

Williamson was born in Auckland but spent nearly all his school years in Matamata. After graduating with qualifications in computer science and applied mathematics from the University of Auckland, he worked for twelve years developing airline planning software for mainframe computers.

Williamson is married to Raewyn and has three children. He is an Honorary Fellow of the New Zealand Computer Society (HFNZCS).

Williamson is a member of Parliament for the National Party, a centre-right political Party in New Zealand, and has been MP for Pakuranga since the 1987 elections. He has held a number of ministerial posts, including Minister of Communications, Minister of Broadcasting, Minister of Transport, and Minister Research, Science and Technology, and associate Minister of Health (1990-6). He was a strong supporter of reform of prostitution law.