The Grey River Argus was a rarity amongst New Zealand newspapers in that it was open about its political affiliations. The Argus supported the Labour Movement. For many years the legend, “New Zealand’s pioneer Labor daily” appeared on the masthead.

The Argus was the first newspaper published in Greymouth, the first issue appearing on 14 November 1865. The publisher, James Kerr (1834-1901), had worked on newspapers in Scotland, Melbourne and Dunedin before coming to Greymouth. He became well known throughout the West Coast through his involvement in local and national politics. He was a close friend of Richard Seddon’s and was a member of the Legislative Council. He remained the principal proprietor of the Argus until his death.

Initially the Argus was published three times a week. In 1871 the paper became a daily. From 1870 to 1907 it published a weekly edition called the Weekly Argus. The Argus survived two fires and several floods in its first few years.

The Argus was fortunate to have several very capable editors in the nineteenth century. These were William Henry Harrison (1831-1879) and Florence Romuald McCarthy (1834-1914). Harrison was editor from 1868 to 1879 and McCarthy from 1880 to 1914. They earned the Argus a national reputation for the quality of its journalism.

Kerr’s son James became manager of the paper after his father’s death and in 1906 formed the Grey River Argus Company. In 1912 the other daily newspaper in Greymouth, the Greymouth Evening Star, considered buying a controlling share in the paper but decided that the price was too high. The next year the Federation of Labour began negotiating with the owners to buy the paper. Most of the New Zealand press were unsympathetic, often hostile, towards Labour. The Federation thought that they needed a paper of their own to counteract this. Buying the Argus made sense given the strong support that Labour enjoyed on the West Coast.

Negotiations were protracted and it wasn’t till 1919 that the West Coast trade unions acquired the paper. However the Argus was, in effect, already a Labour paper by the time it was sold. In 1918 the paper allowed the Grey Labour Representation Committee to use its columns to support Harry Holland contest the Grey seat in that year's election. Future Prime Minister Peter Fraser was responsible for the Labour campaign on the West Coast and wrote editorials for the Argus during this time. The Argus was considered to have contributed to the election of Labour candidates in 1918 for the seats of Grey and Buller.

The early years of the Argus under union management were difficult. The cost of newsprint was high, advertisers were reluctant to use a Labour paper and a few months after assuming control, fire destroyed the Argus office and plant. This was quickly rebuilt by volunteers. The Hokitika Guardian printed the Argus during this time, ensuring that publication was maintained.

The Argus had one rival, the Greymouth Evening Star. The Star began publishing in March 1866. The two papers frequently attacked each other. The Star editorials referred to the Argus as “Labour-Socialists” and the Argus called the Star “Tory-Nationalists”.

In 1966 the Grey River Argus Company was taken over by Buller Westland Publishing Company and the paper was relaunched in February of that year with the new title of the Argus Leader. The Labour affiliation was toned down. “New Zealand’s pioneer Labor daily” was dropped from the front page. These changes failed to save the Argus and it closed in November. The following notice appeared on the front page of the last issue, “Last evening, the directors of the Buller Westland Publishing Co. Ltd., decided that the “Argus Leader” would cease publication with this morning’s issue.”