POLLING stations have opened across Feltham and Heston to find the constituency's next MP.
The parliamentary by-election was sparked by the death of Labour MP Alan Keen, who lost his battle with cancer last month.
Mr Keen held the seat since 1992 and although his majority was cut to 4,658 thanks to a 4.8 per cent swing to the Conservatives at last year's general election, Labour will be hoping to retain the seat.
A private poll carried out at the start of December had Labour candidate Seema Malhotra as the clear favourite, with 52 per cent of the vote, a 22-point lead over the Conservatives on 30 per cent.
The poll, by Conservative donor Lord Ashcroft, interviewed 1,503 adults in the constituency between December 1 and 6, and had the Liberal Democrat candidate, Roger Crouch in third place with 10 per cent of the vote.
Since then, however, David Cameron has enjoyed a notable boost in the polls, following his veto of changes to the European treaty aimed at shoring up the Euro.
This could provide a boost for Conservative candidate Mark Bowen, who lives in the constituency and stood against Mr Keen at the last two general elections.
Last year, Mr Bowen received 34 per cent of the vote to Mr Keen's 43 per cent and will be hoping his work as a councillor in the Feltham North ward helps to sway voters.
Polls will close at 10pm.
The full list of candidates standing is:
David Bishop (Bus-Pass Elvis Party)
Mark Bowen (Conservative)
Andrew Charalambous (UKIP)
Roger Cooper (English Democrats)
Roger Crouch (Liberal Democrat)
David Furness (BNP)
Daniel Goldsmith (Green)
George Hallam (London People Before Profit)
Seema Malhotra (Labour)
