Duncuft was ‘a thorough local man’, whose great-grandfather Isaiah, a farmer, had arrived in Oldham from Cheshire in the early eighteenth century, changing the family name from Duncalf in the process. Duncuft’s grandfather John was, variously, a carter, a farmer and an innkeeper, while his father Isaiah was a glazier, who was ‘casually killed by the fall of his horse’ only two months after Duncuft’s baptism in 1796.
Duncuft’s selection as sole Conservative candidate for Oldham in 1847 was allegedly due to ‘a dearth of local individual capability on the part of the Tories’.
Duncuft is not known to have contributed to parliamentary debate, and on seeking re-election in 1852, was lampooned in an election squib, which under the heading ‘Duncuft’s speeches’ left two blank columns.
Duncuft and Fox ‘almost invariably voted in opposite directions during the whole Parliament’.
Duncuft was considered by Bradshaw’s Railway Almanack as a railway member, but a court case which he pursued against the Lancashire and Yorkshire Railway Company suggested that he was not necessarily the most ardent defender of the railway interest.
Duncuft successfully sought re-election in 1852, when his supporters forged a coalition with the radical John Morgan Cobbett, although a local commentator did not believe that Duncuft himself was privy to this arrangement.
