[1] Masters represented the Taranaki electorate of Stratford from 1919 for the Liberal Party; though the result was declared void in the following year, he won the subsequent 1920 by-election.

[3] Masters was a personal friend of Liberal Party leader George Forbes and the two went for daily walks together.

Notably he was the chairman of the September 1928 convention in Wellington that launched the party's formal existence, decided its policies and where delegates elected former Prime Minister Sir Joseph Ward as its leader.

He also negotiated successfully to bring about co-operation with several independent MPs and candidates (such as Harry Atmore, William Polson and Charles Wilkinson) to support the United Party in the house.

[6] Masters was appointed to the New Zealand Legislative Council on 11 June 1930 and served for one seven-year term.

He was frequently called on to resolve selection disputes as part of the coalition agreement with Reform was to not oppose each others MPs.

He had to work with the Reform leadership to make sure that in as many electorates as possible there was only one "anti-Labour" candidate to avoid vote splitting.