It would not be a coalition- the SNP will not go into coalition, merely allow supply on a measure by measure basis.
What are you basing your analysis on- facts or desires?
In England there is a split between Conservative and Labour which results in large numbers of very safe seats and small numbers of marginals on a regional basis. in Scotland the psephology is different. Most Scottish seats are either three way or two way marginals. This means that in England seats exchange slowly between the two main parties (Conservative and Labour) but in Scotland they exchange quickly on smaller swings.
The only seats not to be marginal in Scotland are
Airdrie and Shotts (Labour)
Coatbridge, Chryston and Bellshill (Labour)
Cumbernauld, Kilsyth and Kirkintilloch East (Labour)
East Kilbride, Strathaven and Lesmahagow (Labour)
Glasgow Central (Labour)
Glasgow East (Labour)
Glasgow South (Labour)
Glasgow (South West)
Glenrothes (Labour)
Inverclyde (Labour)
Kirkcaldy and Cowdenbeath (Labour)
Orkney and Shetland (LibDem)
Paisley and Renfrewshire North (Labour)
Paisley and Renfrewshire South (Labour)
Ross, Skye and Lochaber (LibDem)
Rutherglen and Hamilton West (Labour)
West Dunbartonshire (Labour)
On the above poll (unlikely to be repeated at the ballot box) Labour would win only four seats!) More likely is a retention of a dozen or so
Given the following factors-
Many of the above constituencies voted YES in the referendum.
The Scottish electorate is aware that most of their domestic policies are already decided by Holyrood and are less oriented to ‘electing a government’ rather than electing an MP.
A conservative vote is a wasted vote.
There is a residual bitterness by many against the Unionist parties.
The LibDems have crashed in the polls.
The SNP polled almost fifty percent in the 2009 Scottish Election- people have the experience and memory of voting SNP as Labour voters in referendum and election.
The SNP has nearly quadrupled its membership and is now the third party in the UK.
There remains a nationalist fervour on the streets.
Labour may scupper the vow in an attempt to maintain its majority with Scottish MPs (even though this may become illusory.)
I would get some salt and pepper for your hat if I were you. On these figures I suspect that the SNP will have a solid bloc in Westminster in May and will retain that even in a second election on a hung parliament.
There is likely to be little choice. A Government will have to be made and on likely figures no majority coalition will be available. Even if they go for an October election there is no guarantee that the situation would change that much.
The markets would drop precipitously if we were faced with months or years of no government. The same constraints as 2010 would apply.
I hesitate to bother debating with you Pjen as from bitter experience on specifically Scottish threads and as many of us already know your views cannot be influenced by facts or likelihood but only your bias, so it is more than ironic you are trying to allege the same applies to me.
There is an excellent analysis in this mornings Scotsman (p4 by John Curtice) which shows the underlying numbers are heavily against the SNP scoring the breakthrough some headlines suggest. The SNP lie second to Labour in relatively few constituencies and thus need a massive swing is needed to produce the result you are suggesting, or anything like it.
The SNP need a double digit swing just to get within sight of Labour in Labour held seats. Even a 12 point swing sees no more than seven seats switch from Labour to SNP, and even then in most cases it would only just be enough. This is one poll - experience should tell you not to get overexcited on one poll - especially one taken in the middle of Labour making the front pages for the wrong reasons. A week is a long time in politics and I expect the swing to be much less come election day - it generally works that way for incumbents.
My prediction of yesterday suggested a gain of 7 seats for the SNP - interestedly exactly what Curtice’s detailed analysis suggests as the result for what would already have to be a huge 12 point swing. I just don’t see the swing as ending up bigger than that come election time.
You know my distaste for all Nationalists, where ever they are, but I have no Labour dig in this fight. Labour should recover and the SNP will gain seats but I am sticking to my 13 seat total prediction - and for good reasons.
But let us not allow this thread to be hijacked by Scottish politics - lets move back to a UK wide discussion please.
Clarification - I omitted the word “close” in typing my post above. Labour lie a close second to the SNP in relatively few constituencies… the rest stands.
Some have mentioned here the possibility of a short Parliament and a snap election in late 2015 or early 2016. Assuming we get a dead heat in May, how likely would a rerun be? It seems a lot of the parties are suffering critical funding crises, and may be utterly spent if May is such a close one. Neither side may feel that they have the strength to win and/or fend off smaller parties again.
Some relevant information on that point from the Electoral Commission. The Conservatives have raked in over £7 million in 2014 Q2 alone. Labour are second, with £5.5 million in 2014 Q2, and the Liberal Democrats third with £1.5 million. UKIP and the SNP are both almost equally tied, raising about £1 million. The Tories also collected more in 2014 Q1 as well, although Labour were a lot closer in terms of donations then. The trend seems to have been reversed in 2013 with Labour doing well and the Tories in second place.
If I remember correctly, back in 2010 if the negotiations to form the current coalition had collapsed and another election was called, the Conservatives were projected to win an outright majority due to the amount of excess money they had over the other parties.
tl;dr: in funding terms: Labour and Tories are behemoths, UKIP, Liberal Democrats and SNP are small fry.
Can there be a “snap election” now we have fixed term Parliaments?
I have not looked into the small print, perhaps there are some exceptions allowing one to be called, but absent the parties all agreeing to repeal that legislation in what circumstances could it even happen?
Yes. There’s two ways to call an early election, either by calling a successful no confidence vote in the government, or for two thirds of the Commons to vote for an early election.
The SNP are only contesting 59 seats of course, which makes their war chest look pretty useful, particularly as compared to Labour’s.
You fail to consider the likely home of the 2010 LibDem votes in 2015. The SNP is the likely recopient of these and fleeing Labour votes, making being a close second to a heavily declining Labour unimportant. What is important is the number of available votes from both failing parties.
Whatever keeps your faith alive, Pjen, is what you will believe. I am pretty much done with you but interested in the rest of the debate.
I cannot find the Curtice article online. Reference please. Note that a second poll puts the SNP at 43%
A second election is dependent as in 1974 with the possibility of consolidation into a majority government. My point is that with so many votes not available for government making, a second election is unlikely to result in improvement of the chances for a majority government.
Neither of which are likely. Lambs do not vote for slaughter and everyone is hoping for an improvement. No more by elections can happen now. It will be May as planned.
Even if an election were called it would be a winter one with all that incurs over turnout.
How do you answer the preponderance of three way marginal in Scotland. Effectively two thirds of constituencies are marginal and only six are safe seats. With a volatile electorate and joint collapse of LibDem and Labour since 2010, the SNP look well placed.
It isn’t available online yet - have no idea if it will be or when. Go and buy a copy you cheap skate! 
I will wait for it to be available online when all can see it. Luckily other people are somewhat more appropriate when asked for references, especially those that are not widely distributed. Manners cost nothing.
I note that you are unwilling to discuss an important difference between swing in English and Scottish constituencies.