[1][2] His father was a chartered accountant from Hilton Park, Prestwich, and John was educated at Manchester Grammar School before entering the University of Oxford.
[1][2] Astbury established a legal practice in Manchester, principally dealing with cases at the Palatine Chancery Court and at the Lancashire Assizes.
There was a large swing to the Liberals, and Astbury unseated the Conservative Member of Parliament, Edward Marshall Hall, a fellow barrister.
His injunction on 11 May in favour of the National Sailors' and Firemen's Union of Great Britain was arguably instrumental in ending the strike on the following day.
[2][7] Astbury had been made an honorary fellow of Trinity College in 1923 and on his retirement donated a large collection of legal textbooks and judgements to his alma mater.
Following her death in 1923, he married Harriet, widow of Captain Morrell Andrew Girdlestone and daughter of George Holmes of Philadelphia, Pennsylvania (USA).