During the years he was working at Hutchinson's in Widnes, Brunner was developing his political interests. He joined the Widnes chapter of the National Education League and became its secretary in 1872. This gave him the opportunity to come into contact with Liberals from Liverpool and other parts of the country. Soon after moving to Northwich Brunner became more practically involved with education locally, in particular with the British School in the town. He later served on its board of governors and also on the local sanitary authority. As a result of the Redistribution of Seats Act 1885 the parliamentary constituency of Northwich was created and Brunner offered himself as a candidate for the Liberal Party. In his speech for the position he expressed support for the disestablishment of the Church of England, for reform of property laws, for Irish Home Rule and for compensation for those whose properties had been damaged by the pumping of brine from the salt mines in the area. During the campaign he was heckled because he had a foreign-sounding name. He responded "My father was a Swiss, my mother was a Manx woman, I was born in Liverpool, my nurse was Welsh: is that Cheshire enough for you?" At the general election on 1 December 1885 Brunner beat William Henry Verdin, his Conservative rival, with a majority of 1,028.