He held the office of Serjeant-at-law (Ireland) and in that capacity played a crucial role in the Dublin Castle administration from 1696 to 1711.
During the latter session, he played a leading part in the impeachment of Sir Charles Porter, the flamboyant and controversial Lord Chancellor of Ireland, for what were vaguely described as "high crimes and misdemeanours".
He argued that Neave was highly regarded by the Law Officers and had been recommended by several influential peers, and that it was vital for the Government to have gifted lawyers to manage its legal business in the Commons.
He played a leading role in the Irish Government until 1711, when the new Tory administration dismissed him on strictly political grounds.
By Act of Parliament of 1706 he was constituted one of the trustees for dealing with forfeited rebels' estates, to be used for the purposes of building churches and augmenting the livings of poor vicars.