The by-election is the first since the general election Campaigning in the Oldham East and Saddleworth by-election is into its final day, with parties seeking support ahead of Thursday’s vote.
Candidates will be canvassing across the constituency, which Labour’s Phil Woolas won at the general election.
David Cameron, Ed Miliband and Nick Clegg have all visited the Greater Manchester seat in recent days.
The by-election was prompted after Mr Woolas was barred from Parliament for making false statements about a rival.
At the general election Mr Woolas got 31.9% of votes and Lib Dem Elwyn Watkins 31.6%, with Conservative Kashif Ali on 26.4%. The BNP got 5.7% of votes, UKIP 3.9% and the Christian Party 0.5%.
Turnout in the contest was 61.2%, below the overall UK figure of 65.1%.
The by-election is the first to be held since the last election, making it the first significant test of the coalition government’s popularity.
The contest was triggered after a court found that former Mr Woolas, the former immigration minister, had made false statements about Mr Watkins in last year’s campaign and invalidated the poll outcome.
It also barred Mr Woolas from standing for public office for three years.
Mr Clegg has said Oldham and Saddleworth’s voters face a “simple choice” between his Liberal Democrats and Labour.
But Mr Miliband has urged people to “send a message” to the government over its spending cuts.
Meanwhile, Mr Cameron has rejected claims that the poll amounts to a referendum on the Conservative-Lib Dem coalition.
The full list of candidates (in alphabetical order) is:
Debbie Abrahams (Labour)Derek Adams (British National Party)Kashif Ali (Conservative)Peter Allen (Green Party)David Bishop (Bus-Pass Elvis Party)The Flying Brick (Monster Raving Loony Party)Loz Kaye (Pirate Party of the United Kingdom)Stephen Morris (English Democrats)Paul Nuttall MEP (UK Independence Party)Elwyn Watkins (Liberal Democrats)
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