[1] Born in Jarrow, Johnston left school at the age of eleven to work in the office of Palmers Shipbuilding and Iron Company.
[2] At the 1885 general election, Johnston stood unsuccessfully as an Independent Liberal-Labour candidate in Jarrow, taking 1,731 votes and second place.
At the 1895 general election, the ILP's Prospective Parliamentary Candidate for Manchester North East, Leonard Hall, withdrew at short notice due to a lack of campaign funds, and Johnston stepped in, although he took only 546 votes.
At the 1900 general election, he stood in Ashton-under-Lyne, again at short notice, on this occasion for the Labour Representation Committee, but with the support of the ILP.
[2] In his spare time, Johnston founded a boys' activity club, then ran seaside camps for young girls, to enable them to go on holiday.