He sold this company in 1900 and transferred his business interests to the manufacture of bricks, first through the firms of B J H Forder Ltd. originally a small works on the Gault at Westoning, later taking larger premises at Wootton Pillinge, later renamed Stewartby after the Stewart family.

Towards the end of 1924 he set up the Halley Stewart Trust for Research towards the Christian Ideal in all Social Life,[9] to promote religion, education and the relief of poverty.

[10] His trust donated money to important medical research into asthma, cancer and multiple sclerosis[11] but one of its most important contributions was to sponsor the scientific research of Professor Edward Victor Appleton, of King's College London,[12] whose contributions to the knowledge of the ionosphere led to the crucial wartime innovation of radar.

[1] He also gave money to the district council at Harpenden in Hertfordshire towards the purchase of the manorial rights of the common and his residence The Red House with land and cottages to be used by the town as a hospital after his death.

Thanks to his success as a public speaker, he was invited in the spring of 1884 to make a speech at Boston in Lincolnshire in support of a friend William Ingram.

However, in 1887, the sitting Unionist MP, Murray Finch-Hatton, went to the House of Lords as Earl of Winchelsea in succession to his brother, causing a by-election.

[24] Stewart won the contest by an unexpectedly comfortable margin of 747 votes compared to his loss by 288 in 1886,[25] delighting party colleagues who thought it a great blow to the government.

[26] His opponent, admiral George Tryon had returned from a 2-year tour of duty in Australia only one month before and it was considered his lack of agricultural experience had counted against him.

[35] In 1911, Stewart was one of the large number of names on a list of potential peers which prime minister H H Asquith drew up during the constitutional crisis around the People's Budget and the Parliament Act.

However, in 1932, at the age of 93, Stewart was created a Knight Bachelor in the New Year's Honours list for philanthropic and social services,[37] and was elected a Fellow of King's College, London in 1936.