Voting is set to get under way in the Norwich North by-election with Labour seeking to defend a 5,459 majority.
Voters are heading to the polls in the Norwich North by-election.
It is the first Parliamentary contest since the MPs' expenses scandal broke - the episode which led to the sitting Labour MP Ian Gibson deciding to quit.
It is the first Parliamentary contest since the MPs' expenses scandal broke and was forced by sitting Labour MP Ian Gibson's decision to step down.
Labour has held the seat since 1997 but David Cameron now hopes to take it back for the Conservatives, under a year away from the next general election.
A total of 12 candidates are standing in the election with voting from 0700 BST to 2200 BST. It is expected to be mainly dry with some rain later.
A total of 12 candidates are standing in Thursday's election.
Unusually for a by-election counting will not begin until Friday morning with a result due at about 1200 BST.
The polls will open at 0700 BST and close at 2200 BST.
Counting will not begin until Friday morning with a result expected about 1200pm BST.
The Tory leader has visited the constituency five times in the last few weeks as the party has put its full weight behind candidate Chloe Smith in the hope of victory.
Cabinet ministers Alistair Darling, Hilary Benn and Jack Straw are among senior Labour figures who have been up to the constituency to back Labour candidate Chris Ostrowski.
But Mr Ostrowski's campaign took a hit on Tuesday when it was announced he was being treated for suspected swine flu.
Lib Dem leader Nick Clegg has also been up to the constituency several times to support the party's candidate April Pond.
The Greens are also hoping to make an impact in the area with their candidate, Rupert Read.
They have seven seats on the county council and are the main opposition group on the city council.
Glenn Tingle, the UKIP candidate and Robert West for the BNP will be hoping to gain from the backlash against mainstream parties resulting from the expenses revelations.
One of the independents standing, former ambassador to Uzbekistan Craig Murray, is campaigning under the title "Put an honest man into Parliament".
The remaining independents standing are Laud Howling, on behalf of The Official Monster Raving Loony Party, Thomas Burridge for The Libertarian Party and Anne Fryatt is representing the None of The Above Party.
Peter Baggs and Bill Holden are also standing as independents.
The full list of candidates (in alphabetical order):
The full list of candidates (in alphabetical order):
Peter Baggs (Independent)
Peter Baggs (Independent)
Thomas Burridge (Libertarian Party)
Thomas Burridge (Libertarian Party)
Anne Fryatt (None of The Above Party)
Anne Fryatt (None of The Above Party)
Bill Holden (Independent)
Bill Holden (Independent)
Laud Howling (The Official Monster Raving Loony Party)
Laud Howling (The Official Monster Raving Loony Party)