Born in Shoreditch in the East End of London, Barker was educated at St John's School in Hoxton before following his father in becoming a builder.
An organising committee was established later in 1888, with Barker and John Lincoln Mahon as joint chairs, and the party was officially formed at the start of 1889.
In June, he was a founder of the newspaper Police and Public; this soon became the Illustrated Weekly News, and Barker contributed articles on the proceedings of the new county council, but the paper closed by the end of the year.
[1] Barker was secretary of the printing committee for the 1896 Congress of the Second International, held in London, working on this closely with Harry Quelch and Will Thorne.
[1] During this period, Barker continued to work as a builder, and was active in the Amalgamated Society of House Decorators and Painters.