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6 May 2015, 19:24
The outcome of what looks set to be the closest-fought General Election in a generation will unfold as the results come in a series of key constituency battles across the country.
The first solid indications as to which way the night is going is likely to come from a couple of key Tory marginals in the Midlands - Nuneaton and Northampton North - seen as must-wins for Labour if Ed Miliband is to stand a chance of making it to No 10.
A Labour gain in Carmarthen West and South Pembrokeshire could be a sign that the party is on for a good night - at least in England and Wales.
In Scotland, the full scale of the SNP's surge may become apparent with the declaration in Gordon Brown's old seat of Kirkcaldy and Cowdenbeath where Labour is defending a massive majority of almost 30,000.
Victory for the nationalists in the former Prime Minister's old stamping ground could signal that they really are on course for something like the clean sweep some of the opinion polls have been suggesting.
Such a swing to the SNP could see two of Labour's biggest names in Scotland - shadow foreign secretary Douglas Alexander (Paisley and Renfrewshire South) and Scottish Labour leader Jim Murphy (East Renfrewshire) - blown away in the carnage.
The Liberal Democrats are also unlikely to escape the nationalist advance with Treasury Chief Secretary Danny Alexander potentially their most high profile casualty in Inverness, Nairn, Badenoch and Strathspey.
Former Lib Dem leader Charles Kennedy may also be vulnerable in Ross, Skye and Lochaber while former SNP leader Alex Salmond is plotting a Westminster comeback in Lib Dem-held Gordon.
Labour will need to make good their losses in Scotland with gains in England where their targets include two of the Conservatives' most high profile women - Education Secretary Nicky Morgan in Loughborough and Employment Minister Esther McVey in Wirral West.
Other seats where they will hope to make ground include Enfield North, Erewash and Croydon Central, while wins in Pendle, High Peak or Vale of Glamorgan could point to a very strong result for Mr Miliband.
An even bigger coalition scalp would be Nick Clegg - although the Lib Dem leader appears increasingly confident that he will fight off a strong Labour challenge in Sheffield Hallam.
In the battle with Labour, the Conservatives will be looking to mount successful defences in seats such as Stockton South, Pudsey and Ipswich and may even hope to snatch gains in ultra-marginals like Hampstead and Kilburn and Wirral South.
The Tories will also be pressing the Lib Dems such as Business Secretary Vince Cable in Twickenham as well as in their traditional strongholds in the South West like St Ives and North Devon.
The election will also be a measure of the progress made by Ukip after their triumph in last year's European elections.
Conservative-held Thurrock and Castle Point and Labour-held Great Grimsby are among the seats where they have been campaigning hard.
Of their two defectors from the Conservatives, Douglas Carswell is tipped to hold on in Clacton but Mark Reckless may face more of a fight in Rochester and Strood.
However the real acid test for the party will come in Thanet South where Nigel Farage has said he will stand down as leader if he fails in his challenge to take the seat from the Tories.
Elsewhere Respect's George Galloway is fighting to retain Bradford West after his shock by-election win in 2012 while the Greens' only MP in the last parliament, Caroline Lucas, is battling a Labour push to unseat her in Brighton Pavilion.