In honour of the first 100 days of the Tory/Libdem Coalition the BBC decided to fun a feature on what if they hadn't got together (http://www.bbc.co.uk/news/uk-politics-11009623)
Although they discussed a Tory minority they very briefly touched upon any other make up of a coalition they focused mainly on the Lib Dems and their internal divisions.
I disagree with this approach and so shall provide a few different coalition make ups with perhaps overly simplistic deals
Current Parliament make up - Conservatives (C)-305 , Labour (L)-256, LibDem (LD)-57, (DUP)-8, (SNP)-6, Sinn fein-EXCLUDED, Plaid Cymru (PC)-3, (SDLP)-3, Alliance (A)-1, Green (G)-1, Lady Hermon (LH)-1
Seats needed for majority - 321 (taking into account Sinn Fein, Speaker and Deputies)
1- L/LD/DUP/Hermon=322- A Lab/Lib Coalition backed up by a Joint Unionist contingent of the Independent lady Hermon and the DUP, Lady Hermon during her time in Westminster has often voted with labour and was seen as Left wing within the UUP when she was a member it would most likely be quite easy to convince her to support if not join a Lab/Lib coalition. The DUP meanwhile could be tempted to joint he coalition with a number of methods, firstly by joining government and tackling the UK's problems they could be seen in northern ireland as legitmately trying to bring Northern Ireland closer to the UK mainstream and would score major points with Unionists, relying on solely Northern Irish MPs would mean any coalition would simply have to lessen the cuts on northern ireland which was already deemed to less of a target due to potential dissident feeling, therefore PR+Power+Preferential Budget could build this majority.
2- L/LD/SNP/PC=322- Lab/Lib again only this time back up by the 'Celtic Bloc'. With Plaid already in Coalition with Labour in the Welsh Assembly it would be logical to assume the One Wales government could work together. Plaid would most likely ask for funding system reform which Labour supports. SNP could be brought in with promise of Devolution MAX by end of the parliament as a compromise from their stance on independence. All four parties are left of Centre meaning likely policy agreement.
3-L/LD/SNP/PC/SDLP=325- Option 2 only bringing in the SDLP, as a Labour sister party it is logical to conclude they would support Labour, PR bonus to boost them against Sinn Fein in similar way to the DUP in option 1. Could Prompt more Co-operation from Plaid as they would not necessarily be needed.
4-L/Ld/SNP/PC/SDLP/A=326- Same again only including the Alliance party (libdem sister party) has added bonus of being parliamentary majority if Sinn Fein and Speakers were included. To add to options 2 and 3, SNP given Scottish Ministry, PC given Wales, SDLP given Northern Irish office and Alliance given Communites, give all parties a Cabinet seat with relevancy to their geographical support and Alliance communities as they the PR boost to the building communites across the UK would strengthen them in coming assembly election.
5-(The Anti-tory Alliance) L/LD/SNP/PC/SDLP/A/G/Hermon=328- An anti-tory rainbow alliance, All involved are of the left so ideology conflict would be less of a problem, DUP probably wouldn't work with nationalists and may sign on with the Conservative splitting parliament 328/314. Not Necessarily coalition of all parties but broad agreement to support Centre-left Government if full coalition was agreed include seats from option 4 and include Greens with Enviroment and Lady Hermon in Senior Position if not Cabinet.
6- L/LD/SDLP/PC/A/(H/G)=321- Majority using the sistrer parties and One Wales government with either Lady Hermon or the Sole Green MP. Removes the more radical nationalist of the SNP and built on solid relationships.
There is no other probable coalition other than Con/Lib that results in Conservative led majority.
If you find yourself reading an article on the coalition you will often find it said that 'A lab/lib coalition would be scurrying for votes on every issue' treat it as bollocks... strong words I know but take into account some facts
Despite what the news says, only 321 seats are needed for a parliamentary majority
Lab/Lib brings 313 seats 8 short of majority
the SDLP and Alliance party are the sister parties of Lab/Lib (4 seats in total)
The DUP are Nationalist in the same way as Plaid, they don't want out of UK they just want best deal for Northern Ireland.
The DUP are the only party other than libdem that would be likely to sign up with the Conservatives, this gives them 313 seats.
The SNP and Plaid form the Celtic bloc. (9 Seats)
Labour and Plaid are already in coalition in Wales.
A Coalition agreement would set out how the coalition would function within the parliament, there would be very little scurrying for votes as the parties would already know what the plan is ahead of time