At the time politicians normally needed to rely on a supplementary career for income, and Merriman found a secure secondary occupation as a wine farmer at Schoongezicht, Stellenbosch, after having unsuccessfully tried a range of different professions, from surveyor to prospector to factory manager to merchant.

By 1875 however, he had converted completely, and the leader of the responsible government movement, now the Cape's first Prime Minister, John Molteno, recognised the young Merriman's competency and invited him to serve in his cabinet.

Merriman vigorously supported Molteno in rejecting Lord Carnarvon's ill-considered attempt to enforce a Confederation on the various states of southern Africa.

The Colonial Office eventually overthrew the elected Cape Government in 1878, and forced the Fengu-Gcaleka, Anglo-Zulu and First Boer Wars, before the Confederation scheme finally failed as predicted.

[3][4] Merriman swiftly became the leading opponent of Sir John Gordon Sprigg, the new pro-imperialist Cape Prime Minister appointed by the Colonial Office.

After the fall of the Sprigg government, the volatile Merriman was not backed as the new Prime Minister, even though he had led the opposition, and the "safe" Thomas Charles Scanlen was elevated to the position instead.

[5] It was during his time in the Scanlen Ministry that Merriman rashly criticised the leader of the powerful Afrikaner Bond party, Jan Hendrik Hofmeyr, accusing him of accentuating racial divisions and famously dubbing him "the mole" for his work behind the scenes of parliament.

[6] From 1884 until 1890 he operated as a renegade liberal critic of the Upington and the second Sprigg ministry, politically isolated except for his friends JW Sauer and James Molteno.

With jingoist feeling running high from the Boer War, anti-war politicians suffered electoral losses across the Cape in the following years, and Merriman even lost his seat in parliament for a brief period.

During the union negotiations, he fought to extend the multi-racial "Cape Qualified Franchise" system (whereby suffrage qualification applied equally to all male citizens, regardless of race) to the rest of South Africa.

This decision, inspired partly by British liberal guilt over the Boer War and a desire to make reparations to the Afrikaner people, ended up empowering reactionary political elements of the Transvaal and cementing the franchise distinctions across the new country.

John Molteno noted this change with great approval in 1874 before appointing Merriman to his first cabinet position, and credited the persuasive arguments of liberal parliamentarians such as Saul Solomon as the transforming influence (Cape Argus, 1874).

[10] For much of his career, in spite of his obvious ability, Merriman found himself in a liberal minority — fighting on two fronts against both the pro-imperialist "Progressives" of Rhodes and Milner, and the reactionary nationalism of the Afrikaner Bond.

In July 1907, some of his closest allies Antonie Viljoen, JW Sauer and James Molteno were supporting an extension of the right to vote to women, however Merriman vigorously (and successfully) opposed them in a long, and very bitter, debate.