Sparrow is from Dunville, which amalgamated into Placentia in 1991. As a teenager, he was involved with the Liberal Youth Movement which supported Premier Joey Smallwood's election in the district of Placentia East.[2]
He first attempted to enter the House of Assembly as the candidate for the provincial Liberal party in the redistributed riding of Placentia in 1975, but he narrowly lost to his Progressive Conservative (PC) opponent William G. Patterson. In the subsequent 1979 election, he made another run for the same seat, but lost the Liberal nomination to William Hogan. He contested the seat as an independent candidate where he was again defeated by Patterson.
Sparrow successfully returned to provincial politics in the 1996 election, where he narrowly defeated PC MHA Fabian Manning as the Liberal candidate in Placentia-St. Mary's. He was appointed to the Government Services Committee by Premier Brian Tobin.[3] Manning regained his seat in the 1999 election.
Following his defeat, Sparrow became the Liberal candidate in a 2000 by-election for the federal riding of St. John's West which had been triggered upon the resignation of the incumbent PC Member of Parliament (MP) Charlie Power. Sparrow defeated Steve Kent, then the deputy mayor of Mount Pearl, in a nomination contest bolstered by support from his hometown of Placentia.[1] Despite what was described by The Globe and Mail as "an all-out effort" by the Liberal party to promote his candidacy, Sparrow lost the election to PC candidate Loyola Hearn.[4]