
Tomorrow, voters go to the polls in the closest election for four decades.

Labour’s collapse in Scotland means Ed Miliband will almost certainly miss out on the 323 seats needed for a majority.

For millions, the nightmare is a minority Labour administration propped up by the SNP — which is demanding a £148billion debt binge to pay for more spending and welfare.

Here, JAMES SLACK and IAN DRURY detail the 50 seats in which tactical voting could prevent a Labour/SNP alliance having enough to run Britain — and keep Red Ed out of No. 10.

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In all the seats outside Scotland, they are constituencies in which Labour is either first or second and desperately needs to win. Crucial to the success of tactical voting is reuniting the conservative Right.

There are 29 seats where the Tories have a vastly improved chance of success if they can win the support of Ukip sympathisers.

There are also two Labour seats in the North of England where Cameron’s party cannot realistically win — but Ukip can, so Tory sympathisers should vote for Nigel Farage’s party.

If the Tories do fall short of an overall majority, ensuring Lib Dem candidates beat Labour rivals increases the chances of Nick Clegg’s party having enough seats to form another Coalition with the Tories.

There are 12 seats where Tory voters can help the Liberal Democrats beat Labour. The Lib Dems can reciprocate by voting Tory in three Conservative/Labour marginals.

And there are four seats where Lib Dem and Ukip supporters could vote blue to defeat Labour . . .

The 50 key constituency seats where tactical votes could help to keep a Labour government fronted by leader Ed Miliband (pictured) out have been revealed

1. AMBER VALLEY

Tory (maj: 536)

Odds: Labour 4/7, Tory 6/4, Ukip 14/1

Defending Tory MP Nigel Mills was trailing Labour 37 per cent to 33 per cent in a recent poll. Ukip doesn’t believe it can win — but, if some of the 22 per cent planning to support the party switch sides, Labour will lose.

Tactical vote: Ukip supporters should vote Tory.

2. BERMONDSEY & OLD SOUTHWARK

Lib Dem (maj: 8,530)

Odds: Lib Dem 8/15, Labour 11/8, Tory 100/1

A Lord Ashcroft poll found Lib Dem justice minister Simon Hughes had just a one point lead over Labour, while the Tories are no-hopers.

Tactical vote: Tories should vote Lib Dem.

3. BIRMINGHAM YARDLEY

Lib Dem (maj: 3,002)

Odds: Lib Dem 5/6, Labour 5/6, Ukip 50/1, Tory 100/1

The Tories have no chance in this Midlands seat, but their supporters can help Lib Dem open justice campaigner John Hemming triumph over Labour’s Jess Phillips.

Tactical vote: Tories vote Lib Dem.

4. BLACKPOOL NORTH & CLEVELEYS

Tory (maj: 2,150)

Odds: Tory 1/3, Labour 2/1, Ukip 25/1

Tory Paul Maynard would be more confident of victory over Labour’s Penny Martin if he could bank on the support of the 15 per cent planning to support Ukip.

Tactical vote: Ukip vote Tory.

5. BOLTON WEST

Labour (maj: 92)

Odds: Labour 1/8, Tories 5/1, Ukip 28/1

The Tories were hopeful of success here after securing a 5.9 per cent swing in 2010, but plans have since been derailed by a huge surge in support for Ukip, which has been polling at 21 per cent.

Combined, the Tory and Ukip support would stand at 48 per cent — enough to defeat Labour’s Julie Hilling.

Tactical vote: Ukip vote Tory.

6. BRADFORD EAST

Lib Dem (maj: 365)

Odds: Labour 2/7, Lib Dem 5/2, Tory 28/1

Recent polling gave Labour’s Imran Hussain a 22-point lead over sitting Lib Dem David Ward. Tory voters can save Ward in a seat where jobs and house-building on green land are hot local issues.

Tactical vote: Tories vote Lib Dem.

7. BRIGHTON KEMPTOWN

Tory (maj: 1,328)

Odds: Labour 4/6, Tory 11/10, Ukip 100/1

Labour has edged into a narrow lead in this bellwether constituency — but sitting MP Simon Kirby will triumph with a decent share of the votes of the 13 per cent who recently said they were voting Ukip.

Tactical vote: Ukip vote Tory.

8. BRISTOL WEST

Lib Dem (maj: 11,366)

Odds: Labour 2/7, Green, 9/2, Lib Dem 11/2, Tory 100/1

The latest poll in the constituency put Lib Dem Stephen Williams 18 points behind Labour’s Thangam Debbonaire and third behind the Greens. Tory votes could swing the seat back in his favour.

Tactical vote: Tories should vote Lib Dem.

9. BROXTOWE

Tory (maj: 389)

Odds: Labour 4/9, Tory 15/8, Ukip 28/1

In 2010 Anna Soubry took a seat held by Labour’s Nick Palmer since 1997. Labour lead in the polls — but a little over half of Ukip’s support breaking for the Tory defence minister would swing the contest her way.

Tactical vote: Ukip vote Tory.

10. BURY NORTH

Tory (maj 2,243)

Odds: Labour 1/2, Tory 6/4, Ukip 33/1

Eurosceptic MP David Nuttall presented David Cameron with a 100,000 strong petition for an in/out referendum on the UK’s membership of the EU. Ukip supporters can help him defeat Labour.

Tactical vote: Ukip supporters should vote Tory.

11. CAMBRIDGE

Lib Dem (maj: 6,792)

Odds: LibDem 1/3, Labour 9/4, Tory 33/1

Polls have given LibDem civil liberties campaigner Julian Huppert a lead of only one point over Labour’s Daniel Zeichner. The Tories have little chance of winning the seat — but they could save Mr Huppert.

Tactical vote: Tories vote Lib Dem.

If the Tories do fall short of an overall majority, ensuring Lib Dem candidates beat Labour rivals increases the chances of Nick Clegg’s party having enough seats to form another Coalition with the Prime Minister David Cameron (pictured above) and his Conservative party

12. CARDIFF CENTRAL

Lib Dem (maj: 4,576)

Odds: Labour 1/7, LibDem 4/1, Greens 33/1, Tory 50/1

The bookies make Labour’s Jo Stevens — ahead 36 to 24 in one Ashcroft poll — favourite to topple Jenny Willott. The Tories, on 17 per cent, could help the Lib Dem cling on to the seat.

Tactical vote: Tories vote Lib Dem.

13. CARDIFF NORTH

Tory (maj: 194)

Odds: Labour 2/9, Tories 11/4, Ukip 100/1

Tory Craig Williams was 11 points behind Labour in one recent poll. Ukip was on 12 — potentially making the crucial difference.

Tactical vote: Ukip vote Tory.

14. CARLISLE

Tory (maj: 853)

Odds: Labour 1/3, Tory 9/4, Ukip 33/1

Tory John Stevenson was recently 11 points behind Labour in a contest bookies say is a straight fight between the two main parties. Ukip was on 18 per cent — with it supporters having the ability to keep Labour out.

Tactical vote: Ukip vote Tory.

15. COLNE VALLEY

Tory (maj: 4,837)

Odds: Tory 4/9, Labour 13/8, Ukip 66/1, Lib Dem 100/1

Last month, an Ashcroft poll had defending Tory MP Jason McCartney on 33 per cent, Labour on 32, Lib Dems on 12 and Ukip on 11 in a seat where Europe and the EU have been regularly debated.

Tactical vote: Lib Dem and/or Ukip vote Tory.

16. CORBY

Labour (maj: 7,791)

Odds: Labour 2/7, Tories 11/4, Ukip 18/1

Labour’s Andy Sawford, who won Louise Mensch’s former seat in a 2012 by-election, recently held a ten-point lead over the Tories. But borrowing half the Ukip vote could give Tory Tom Pursglove victory.

Tactical vote: Ukip vote Tory.

Tory Anna Soubry (left) is trying to retain her seat in Broxstowe, Nottinghamshire, while Liberal Democrat women’s minister Jo Swinson, (right), who was elected at the age of 25 in 2005, is facing an uphill task to hold back the approaching SNP tide in East Dunbartonshire

The most marginal seat in the country - Hampstead & Kilburn - is currently held by the Academy Award-winning actress Glenda Jackson (left). Had the Tories borrowed just 50 of the 16,491 votes cast for the Liberals in 2010 they would have won. Lib Dems should vote for the Conservatives to keep out Labour, as they should in Enfield North where Labour's Joan Ryan (right) is re-contesting the seat from 2010

17. CROYDON CENTRAL

tory (maj: 2,969)

Odds: Tories 4/6, Labour 11/10, Lib Dems 100/1

A poll last weekend put Tory Gavin Barwell on 43 per cent — only three ahead of Labour in this crucial marginal. Ukip had ten points — with its voters having a potentially decisive impact.

Tactical vote: Ukip vote Tory.

18. DUDLEY NORTH

Labour (maj: 649)

Odds: Labour 2/9, Ukip 3/1, Tories 20/1

The Tories can’t win here after a disastrous campaign, but with Ukip’s Bill Etheridge only three points behind Labour in a recent poll, they can help to unseat former Gordon Brown spin doctor Ian Austin.

Tactical vote: Tories vote Ukip.

19. EALING CENTRAL & ACTON

Tory (maj: 3,716)

Odds: Labour 1/2, Tories 6/4, Lib Dems 50/1

Recent polling put Labour on 40, six ahead of the Tories. The Lib Dems, at 11 per cent, can’t win, but they do have the votes to save Tory candidate Angie Bray.

Tactical vote: Lib Dems vote Tory.

20. EAST DUNBARTONSHIRE

Lib Dem (maj: 2,184)

Odds: SNP 2/5, Lib Dem 7/4, Labour 25/1, Tory 100/1

Liberal Democrat women’s minister Jo Swinson, who was elected at the age of 25 back in 2005, is facing an uphill task to hold back the approaching SNP tide. One poll put her 11 points behind the Nationalists, but Tory votes may save her.

Tactical vote: Tories vote Lib Dem.

David Cameron with Tory candidate Matthew Offord, who isis facing a renewed challenge from the Labour candidate he ousted at the 2010 election, Andrew Dismore, for the Hendon seat. Labour is currently leading by 15 points

21. ENFIELD NORTH

Tory (maj: 1,692)

Odds: Labour 1/4, Tory 11/4, Ukip 100/1, Lib Dem 100/1

In 2010, Tory Eurosceptic Nick de Bois defeated Joan Ryan — who had been exposed as an expenses cheat. Ryan is re-contesting the seat and was 10 points ahead in a recent poll. If the 12 per cent planning to vote Ukip switched to Tory, the Labour re-tread would lose.

Tactical vote: Ukip and Lib Dems vote Tory.

22. FINCHLEY & GOLDERS GREEN

Tory (maj: 5,809)

Odds: Tory 4/6, Labour 11/10, Lib Dem 100/1

Labour’s candidate, Sarah Sackman, has been eating into the lead gained by Tory Mike Freer in 2010 in a seat where Mrs Thatcher was once the MP. The 8,000 who voted Lib Dem last time could tip the balance.

Tactical vote: Lib Dems vote Tory.

23. GREAT YARMOUTH

tory (maj: 4,276)

Odds: Conservatives 2/5, Labour 2/1, Ukip 12/1

At one time, this was a key target for Ukip (the party polled 32 per cent in 2014), but bookies have now made it a fight between then sitting MP Brandon Lewis and Labour’s Lara Norris. Votes intended for Ukip could dash Labour hopes.

Tactical vote: Ukip vote Tory.

24. HALESOWEN & ROWLEY REGIS

Tory (maj: 2,023)

Odds: Conservatives 4/5, Labour evens, Ukip 20/1.

With immigration a major issue on the doorsteps in this constituency, a surge in local support for Ukip (on 15 per cent) has left defending Tory MP James Morris two points behind Labour. Ukip can’t win — but voters can thwart Labour.

Tactical vote: Ukip vote Tory.

25. HALIFAX

Labour (maj: 1,472)

Odds: Labour 3/10, Tory 5/2, Ukip 25/1

David Cameron launched his General Election campaign in this West Yorkshire town. Labour’s Holly Walker-Lynch is currently leading her Tory rival Philip Allott by 46 to 23, with Ukip (18 per cent) splitting the traditional Conservative vote.

Tactical vote: Ukip vote Tory.

26. HAMPSTEAD & KILBURN

Labour (maj: 42)

Odds: Labour 1/4, Tory 7/2, Lib Dem 12/1

The most marginal seat in the country, currently held by the Academy Award-winning actress Glenda Jackson. Had the Tories borrowed just 50 of the 16,491 votes cast for the Liberals in 2010 they would have won. A tactical vote could allow them in this time.

Tactical vote: Lib Dem vote Tory.

27. HASTINGS AND RYE

Tory (maj: 1,993)

Key battle: Tory v Labour

Odds: Labour 4/9, Tory 2/1, Ukip 16/1

Labour’s Sarah Owen, leading Tory energy minister Amber Rudd by 40 per cent to 31, is being helped by traditional Tory support leaching to Ukip, who are on 19 per cent in one recent poll.

Tactical vote: Ukip vote Tory.

28. HENDON

Tory (maj: 106)

Odds: Labour 1/6, Tory 7/2, Ukip 100/1, Lib Dem 100/1

Tory Matthew Offord is facing a renewed challenge from the Labour candidate he ousted at the 2010 election, Andrew Dismore. Labour is currently leading by 15 points, but borrowing Ukip and LibDem votes could see Mr Offord to an unlikely triumph.

Tactical vote: Ukip and Lib Dem vote Tory.

Voting for Lib Dem Danny Alexander (left) could keep out Labour in the Inverness, Nairn, Badenoch and Strathspey seat. Elsewhere, a vote for Lib Dem leader and deputy prime minister Nick Clegg (right) in the Sheffield Hallam seat could help the Tories get one over on Labour

29. HEYWOOD & MIDDLETON

Labour (maj: 617)

Odds: Labour 1/10, Ukip 5/1, Tories 100/1

Rematch of the knife-edge October 2014 by-election contest when Ukip’s John Bickley came within 617 votes of beating Labour’s Liz McInnes. The Tories can’t win — but they can help Ukip give Red Ed a bloody nose.

Tactical vote: Tories vote Ukip.

30. HORNSEY AND WOOD GREEN

Lib Dem (maj: 6,875)

Odds: Labour 4/11, LibDem 2/1, Greens 20/1, Tory 100/1

Home Office Minister Lynne Featherstone is in danger of being toppled by Labour’s Catherine West, who led 43 to 30 in a recent poll. Last month, a local Tory chairman was suspended for urging Conservatives (14 per cent) to vote Lib Dem — but he had a point.

Tactical vote: Tories vote Lib Dem.

31. INVERNESS, NAIRN, BADENOCH AND STRATHSPEY

Lib Dem (maj: 8,765)

Odds: SNP 1/16, Lib Dem 7/1, Labour 50/1, Tory 150/1

Lib Dem Danny Alexander could become one of the SNP’s most high-profile victims — with polls putting him 29 points behind the Nationalists. The votes of the 6,000 people who voted Conservative in 2010 could save the Cabinet minister

Tactical vote: Tories vote Lib Dem.

32. KEIGHLEY

Tory (maj: 2,940)

Odds: Labour 4/7, Tory 11/8, Ukip 33/1

Recent polls show Ukip would win one in four votes. If just over a quarter of these switched to Tory junior minister Kris Hopkins, who trails Labour re-tread John Grogan by six points, he would win.

Tactical vote: Ukip vote Tory.

33. KINGSWOOD

Tory (maj: 2,445)

Odds: Conservative 1/4, Labour 11/4, Ukip 50/1

It’s vital that Tory Chris Skidmore hangs on to the West Country seat he snatched from Labour in 2010. Ukip support could ease him home in a seat that is high on Ed Miliband’s list of targets.

Tactical vote: Ukip vote Tory.

Home Office Minister Lynne Featherstone (left) is in danger of being toppled by Labour’s Catherine West in Hornsey and Wood Green while Tory voters can help Lib Dem open justice campaigner John Hemming (right) triumph over Labour’s Jess Phillips in Birmingham Yardley

34. LANCASTER AND FLEETWOOD

Tory (maj: 333)

Odds: Labour 2/9, Tory 3/1, Ukip 50/1

Labour’s Cat Smith can take the seat from sitting Tory MP Eric Ollerenshaw on a swing of just 0.4 per cent. The 18 per cent of people who say they were planning to vote for Ukip — which has no chance of winning — could change the outcome of the battle.

Tactical vote: Ukip vote Tory.

35. LEEDS NORTH WEST

Lib Dem (maj: 9,103)

Odds: Lib Dem 4/9, Labour 15/8, Tory 28/1

Lib Dem Greg Mulholland appears to have a comfortable majority, but his party’s U-turn on tuition fees has played badly with local students. Tories can help him to beat Labour’s Alex Sobel.

Tactical vote: Tories vote Lib Dem.

36. LINCOLN

Tory (maj: 1,058)

Odds: Labour 4/9, Tory 7/4, Ukip 20/1

Tory Karl McCartney — who won the seat in 2010 after Labour’s Gillian Merron was ordered to repay £6,300 in the expenses scandal — is trailing 35 per cent to Labour’s 39 per cent, according to an Ashcroft poll, leaving Ukip supporters (18 per cent) as kingmakers.

Tactical vote: Ukip vote Tory.

37. MANCHESTER WITHINGTON

Lib Dem (maj: 1,894)

Odds: Labour 1/16, Lib Dem 8/1, Green 33/1, Tory 100/1

Lib Dem John Leech is 34 points adrift of Labour’s Jeff Smith, according to a recent poll, but if the Greens take chunks out of the Labour vote, and Tories lend him their backing, all is not lost.

Tactical vote: Tories vote Lib Dem.

38. MILTON KEYNES SOUTH

Tory (maj: 5,201)

Odds: Tory 4/7, Labour 5/4, Ukip 50/1

Tory Iain Stewart has a seemingly comfortable majority, but a recent poll put him two points behind Labour rival Andrew Pakes. The support of either the Lib Dems (polling 8 per cent) or Ukip (10 per cent) could swing it.

Tactical vote: Ukip or Lib Dem supporters should vote Tory.

39. MORECAMBE AND LUNESDALE

Tory (maj: 866)

Odds: Labour 1/2, Tory 6/4, Ukip 66/1

Labour’s Amina Lone was recently six points ahead of the Tory David Morris (a musician who once appeared on Top Of The Pops with Rick Astley). Morris could overturn this with Ukip support (12 per cent).

Tactical vote: Ukip vote Tory.

Tory voters could pledge support for Ukip in the Morley and Outwood seat in West Yorkshire to stop Labour's Ed Balls winning and helping the party into power

40. MORLEY AND OUTWOOD

Labour (maj: 1,101)

Odds: Labour 1/33, Tory 10/1, Ukip 20/1

Shadow chancellor Ed Balls’s seat is statistically one of the most vulnerable and could fall on a swing of just 2.25 per cent to the Tories. Who could resist trying to topple the man who helped to wreck the economy?

Tactical vote: Ukip vote Tory.

41. NORTHAMPTON NORTH

Tory (maj: 1,936)

Odds: Tory 10/11, Labour 10/11, Ukip 20/1

Crunch seat seized by Tory Michael Ellis from Labour expenses cheat Sally Keeble. Keeble is standing again and led by four in a recent poll, but Ukip’s 22 per cent of the vote could help Eurosceptic Mr Ellis see off the challenge.

Tactical vote: Ukip vote Tory.

42. NORTH WARWICKSHIRE

Tory (maj: 54)

Odds: Labour 1/3, Tory 5/2, Ukip 16/1

The most marginal Tory seat in the country, the party’s Craig Tracey trails Labour 30 per cent to 41 per cent. But almost one in four voters supports Ukip, and if just over half of those switch to the Tories, Labour would be denied.

Tactical vote: Ukip vote Tory.

43. NORWICH NORTH

Tory (maj: 3,901)

Odds: Tory 5/6, Labour 5/6, Ukip 33/1

Tory Chloe Smith won this key marginal in a 2009 by-election and defended it a year later, but she is behind Labour in the latest polls (35 per cent to 39 per cent). Could be saved with the help of the 14 per cent of voters who back Ukip.

Tactical vote: Ukip vote Tory.

44. PETERBOROUGH

Tory (maj: 4,861)

Odds: Tory 1/2, Labour 6/4, Ukip 33/1

Tory Stewart Jackson has held the seat since 2005. However, a Ukip surge has given Labour a chance in a constituency where immigration is a huge issue — a weekend poll had him trailing 32 per cent to 36 per cent. Ukip supporters (20 per cent) could save the Eurosceptic MP.

Tactical vote: Ukip vote Tory.

45. SHEFFIELD HALLAM

Lib Dem (maj: 15,284)

Odds: LibDem 2/5, Labour 7/4, Tory 50/1

Labour would love to claim Nick Clegg’s scalp (and see the Lib Dems elect a more Left-wing leader who’d be more likely to do a deal with Ed Miliband). Tories should hold their noses and vote for the Deputy PM.

Tactical vote: Tories vote Lib Dem.

46. SHERWOOD

Tory (maj: 214)

Odds: Labour 2/7, Tory 11/4, Ukip 16/1

Coalfields marginal won by Tory Mark Spencer in 2010 after 18 years of Labour rule. His rival is the union-backed Leonie Mathers. A share of Ukip’s predicted 16 per cent vote could be decisive.

Tactical vote: Ukip vote Tory.

47. SOUTHAMPTON ITCHEN

Labour (maj: 192)

Odds: Labour 2/5, Tory 2/1, Ukip 16/1

A swing of just 0.4 per cent would see Labour unseated in this crunch marginal. The 30-year-old Guardian journalist and former Labour councillor Rowenna Davis leads by eight points, but if half of Ukip’s 17 per cent support voted for the Conservative instead, the seat would turn blue.

Tactical vote: Ukip vote Tory

Employment minister Esther McVey (left) is a prized target for Labour in Wirral west but Ukip voters (five per cent) could save her. Meanwhile, Tory James Wharton (right) will be trying to retain his seat in Stockton South, which is favourite to be taken over by Labour

48. STOCKTON SOUTH

Tory (maj: 332)

Odds: Labour 4/5, Tory evens, Ukip 66/1

Held by Tory James Wharton since 2010. He introduced a backbench bill guaranteeing the EU referendum Ukip supporters want — but the move was killed off by Labour, who are favourites to win the seat.

Tactical vote: Ukip vote Tory.

49. STROUD

Tory (maj: 1,299)

Odds: Labour 1/2 , Tory 7/4, Ukip 25/1

Tory Neil Carmichael snatched the seat in 2010. His defeated opponent David Drew, who had been the sitting MP since 1997, is standing again, and a poll put the Labour man up by 11 points — the share of the vote Ukip expects to have.

Tactical vote: Ukip vote Tory.

50. WIRRAL WEST

Tory (maj: 2,436)

Odds: Labour 4/6, Tory 11/10, Ukip 100/1

Prized target for Labour to give Tory employment minister Esther McVey the boot. The former TV presenter trailed by three per cent in a recent poll, but Ukip voters (five per cent) could save her.

Tactical vote: Ukip supporters should vote Tory.