In 1853 Parker was elected to the Nelson Provincial Council as member for Motueka and Massacre Bay, a seat which he held until 1857.
[1] Parker was a populist opposed to the class system and supported John Perry Robinson's programme of liberalising land purchase to prevent the establishment of large landholdings or latifundia.
Parker's local political rival was David Monro, who championed the more conservative 'Supper Party' and large run holders.
In a controversial 1871 election, a recount found Parker and Munro had split the vote equally; the returning officer's casting vote returned Monro as MP, but this was overturned following a petition, and Parker was declared elected.
[1] Parker retired to pursue business interests; by 1882 he owned 53 acres (21 ha) of land in Waimea County, valued at £550.