Arblaster was elected to the New South Wales Legislative Assembly for the Electoral district of Mosman in 1972 and served until his retirement in 1984.

[2] Arblaster contested the 1967 Australian Senate election on the NSW Liberal ticket but was on third position and failed to gain a seat.

[3] Arblaster then stood for and was elected to the seat of Mosman at a July 1972 by-election caused by the mid-term retirement of former Liberal Leader and Minister of the Crown, Pat Morton.

Thereafter he was appointed as Shadow Minister for Public Works, Ports and Housing under Opposition leader Willis until his resignation on 16 December 1977.

Arblaster then announced his intention to contest the vacant leadership against John Maddison, Peter Coleman and Kevin Rozzoli.

After Cox denied this, Arblaster was given several warnings for interjecting before the Speaker, Laurie Kelly, expelled him from the House for 24 hours.

He added not only colour but intelligence and character...he brought vision to his constituency, to the Parliament, and to the people of New South Wales.