In the
1966 general election, MacFarquhar fought the
Ealing South constituency for the
Labour Party but failed to dislodge the sitting
Conservative MP. Two years later, he was Labour candidate who attempted to retain the
Meriden seat in a
by-election; he was on the wrong end of an 18.4%
swing at the height of the
Wilson government's unpopularity. Following the defeat of
George Brown in 1970 and favourable boundary changes, MacFarquhar was selected to fight the
Belper constituency, and at the
February 1974 general election succeeded in winning the seat from its sitting Conservative MP
Geoffrey Stewart-Smith. Although he won, there was an estimated swing of 4% to the Conservatives had the same boundaries applied in the previous election. MacFarquhar proved a moderate figure, in line with Brown's views. He abstained on a vote to remove the disqualification of left-wing Labour councillors in
Clay Cross who had broken council housing laws enacted by the previous Conservative government. However, there were exceptions: he also abstained on a vote to increase the
Civil list payments on 26 February 1975. He acted as
Parliamentary Private Secretary (PPS) to
David Ennals, a minister of the state at the
Foreign and Commonwealth Office, and retained the job when Ennals was promoted to be
Secretary of State for Social Services. He was a member of the Select Committee on Science and Technology. ==After Parliament==