WHY IS THERE A BY-ELECTION IN EASTLEIGH?
The small Hampshire town of Eastleigh was thrown into the political spotlight at the beginning of February, following the resignation of Lib Dem MP Chris Huhne.
The disgraced former Energy Secretary became the only British cabinet member in history to be forced from office by a criminal prosecution, after admitting perverting the course of justice.
Huhne, 58, pleaded guilty to the charge on February 4, which related to speeding points a decade ago.
His resignation sparked a by-election in the constituency where he had been Lib Dem MP since 2005.
Candidates from all three major political parties - as well as several 'less conventional' candidates - are now campaigning to become MP of a town which has turned into a key political battleground.
WHY IS IT SO IMPORTANT?
The by-election in Eastleigh will be the first time the Coalition partners have fought over a single seat since they took shared power in 2010.
Political commentators have speculated that the by-election is a test of David Cameron's leadership of the Conservative Party.
He has already visited the Hampshire town to help canvass for votes with his candidate, Maria Hutchings - who is currently second in early polls behind the Lib Dem's Mike Thornton.
Senior Tories have previously confessed that losing Eastleigh would 'put some real question marks over our election strategy'.
Others say Eastleigh is the most important by-election in 30 years, as the Prime Minister needs a victory to convince his party he can gain a workable majority by 2015.
Candidates have been relentlessly campaigning across the Hampshire town since early February
As well as support from the Prime Minister, Maria Hutchings has also been assisted on the campaign trail by London Mayor Boris Johnson.
The UK Independence Party (UKIP) have a 21% share of support in the town, according to a recent poll by Survation.
The anti-Europe party, whose candidate is councillor Diane James, claim they could cause a 'political earthquake' by winning the Hampshire seat.
WHO ARE THE MAIN CANDIDATES?
The Conservative candidate, Maria Hutchings, stood against Chris Huhne in 2010, but came second.
The hard-working mother-of-four hit the headlines in 2005 when she challenged then Prime Minister Tony Blair during a live TV debate.
Mrs Hutchings, a campaigner for special needs children and carers, showed Mr Blair a photo of her autistic son John Paul, claiming she struggled to get him the speech therapy he needed.
She has campaigned fiercely across the town, but according to recent polls remains neck and neck with Lib Dem candidate Mike Thornton.
Mr Thornton has lived in the Eastleigh area for almost 20 years, and has been a parish and borough councillor since 2007.
He has pledged to protect green spaces, cut income tax for local workers, and bring more jobs and investment to the Hampshire constituency.
The two frontrunners will be mindful of UKIP candidate Diane James, the councillor for Waverley Borough in Surrey who joined the party in 2010.
Sources in Eastleigh describe the healthcare expert as 'more Conservative than the Conservative candidate', and Mrs James has received good support on the doorsteps of the Hampshire town.
Experts say Mrs James 'looks and sounds like a Tory', and with her more centrist views and promises of 'integrity and commitment', could snatch victory from the Coalition partners.
Labour's candidate, broadcaster and author John O'Farrell, is fourth in the popularity stakes, with support of around 11-12 per cent.
He previously stood for the party in 2001 in Maidenhead, and describes himself as a 'lifelong Labour supporter'.
The race to become MP for Eastleigh has predictably drawn a number of less orthodox candidates.
Others in the running include 'Howling Laud Hope' (real name Alan Hope) of the Monster Raving Loony Party, Ray Hall - from the 'Beer, Baccy and Crumpets' party, and David Bishop - from the 'Elvis Loves Pets' party.
Ian Dunt, editor of politics.co.uk, said the Conservatives could be foiled by the Lib Dems' strength in local campaigning.
He said: "Eastleigh is the Tories' first chance to test out the 'weaponised' policy-led campaigning which they plan to use against the Lib Dems in the general election.
"The party needs to take about 20 seats from their coalition partners to be in with a shot of a majority in 2015.
"Unfortunately for the Conservatives, the Lib Dems are seasoned and disciplined local campaigners.
"Even when the national picture is grim, they retain much of their local support – and in a race against the Tories they can rely on Labour supporters to back them as the least worst option.
"It's a timely reminder to those forecasting the end of the Liberal Democrat party that British elections still rely on a great deal of strategic voting."
WHO LIVES IN EASTLEIGH? HOW HAVE THEY VOTED BEFORE?
Created as a constituency in 1955, Eastleigh has an electorate of over 78,000.
Eastleigh had been a safe Conservative seat for four decades until the death of MP Stephen Milligan in 1994.
The Lib Dems took over the constituency with 44% support in the resulting by-election, with MP David Chidgey holding on to the seat until he stood down at the 2005 General Election.
Chris Huhne, the town's most recent MP, took over the same year, before twice launching unsuccessful Lib Dem leadership campaigns in 2006 and 2007.
He lost out to Sir Menzies Campbell in 2006 and Nick Clegg a year later, but joined the Coalition government in 2010 as Energy Secretary.