Heywood and Middleton by-election: Your guide to the 9 October poll
The people of Heywood and Middleton will go to the polls on 9 October to elect the late Labour MP Jim Dobbin's successor.
The former microbiologist, who died on 7 September during a trip to Poland at the age of 73, had been the Greater Manchester constituency's MP since 1997, and secured a 5,971 majority at the 2010 election.
You could say Heywood and Middleton are typical northern towns in a working-class heartland which has been staunchly Labour ever since the constituency was created in 1983.
Heywood, like so many others, was a town built around textile factories but now, with its proximity to the M62, you'll find people working at distribution centres instead.
Middleton, a mixture of Mancunian overspill and leafy garden village, was originally given its name because it was situated in the centre of several settlements.
By Arif Ansari, BBC North West political editor
The central battle in this by-election is between UKIP and Labour. Nigel Farage needs to prove his party can win seats like Heywood and Middleton if it is to become a genuinely national force.
It's not the only political fight, though. At the general election the Conservatives came second, but they would not exactly be upset if UKIP beat Labour. The Lib Dems, meanwhile, will be fighting to hold their election deposit, and fend off a challenge from the Greens.
The constituency is fertile ground for UKIP. It is overwhelmingly white, there is plenty of social deprivation and there is much disillusionment with Westminster.
Many voters believe there has been too much immigration. And few have forgotten that white girls were groomed on the streets of Heywood. UKIP has accused Labour of a "betrayal" of the community. Labour's called that "shameful opportunism". But those separate issues around grooming, immigration and identity have become conflated and are likely to motivate voters.
In February, when UKIP fought the Wythenshawe and Sale East by-election with the same candidate, they came a distant second. This time they have run a sharper campaign and believe more Labour voters are heading their way.
Labour has steadied the ship after a wobbly start to the campaign, and has a large majority to defend. It is not impossible that UKIP could win here, but if they take 30% of the vote it would be substantial progress for them as they try to establish themselves as the main opposition to Labour in the North of England.
Its people could now be at a political crossroads as well.
Jim Dobbin's final few years as MP had been tragically eventful.
Fusilier Lee Rigby, from Middleton, was murdered by Islamist extremists in south-east London in May 2013.
In 2012, Heywood was shocked by a grooming scandal in which white girls as young as 13 were systematically abused by a group of older men.
Nine men - eight of Pakistani origin and one from Afghanistan - were jailed for between four and 19 years.
The authorities were found to have failed to address this criminal activity for years, with some claiming this was down to a fear of being accused of racism.
So could the UK Independence Party, who have highlighted the grooming issue in campaign leaflets, make inroads?
While Mr Dobbin secured 40% of the vote four years ago - with 17,000 more votes than UKIP in fifth and last place - Labour activists have been worried.
UKIP now have three North West MEPs, two Greater Manchester councillors, and in May only missed out on securing their first councillor in Heywood by 23 votes.
Speaking to people in Heywood and Middleton, you get a sense of a community frustrated by the status quo. Disappointed in the local politicians who didn't prevent the grooming and national politicians who they feel have let white working-class people down.
"Too much immigration", "Not enough jobs" is what you hear time and time again.
People who told me they'd voted the same way all their lives said they were now considering a change.
In the face of a potential protest vote, the challenge for Labour will be to get their voters to turn out.
The Conservative, Liberal Democrat and Green candidates also feel they have a strong message to take to people here.
This by-election takes place on the same day as the one in Clacton in Essex, where the Tory MP Douglas Carswell recently defected to UKIP.
Clacton may be UKIP leader Nigel Farage's main target, but Heywood and Middleton will be a good test of his party's claims that they can challenge Labour in the north of England just as strongly as they can the Tories in the south.
While the numbers suggest Heywood and Middleton is Labour's to lose, any sharp reduction in their majority would be viewed by them as a disappointment and a blow to Ed Miliband's chances of ousting David Cameron from Downing Street in next year's general election.
Full list of candidates, in alphabetical order:
Bickley, John - UK Independence Party
Gartside, Iain - The Conservative Party
Jackson, Abi - Green Party of England and Wales
McInnes, Liz - Labour Party
Smith, Anthony - The Liberal Democrats