There is a better than sporting chance that Labour and the SNP could form a coalition after the coming General Election. Polls suggest that Labour will lose the vast majority of the 41 seats they currently hold in Scotland with the SNP having between 30-40+ seats. In addition, despite Labour’s dire present leadership, the national UK polls persistently show the Tories with at best a lead of only a few points and now and then behind Labour by the same margin, this at a time when the Tories need a substantial lead to gain a bare majority in the Commons because of the wide differences in constituency sizes, differences which favour Labour, viz:
“ if you leave the Liberal Democrat share of the vote unchanged then the Conservatives need a lead of 11 percentage points over Labour to win an overall majority, while the Labour party can achieve an overall majority with a lead of about 3 percentage points. Equally illustrative are the last two general election results – in 2005 Labour had a lead of 3 points over the Conservatives, and got a majority of over 60 seats; in 2010 the Conservatives had a lead of 7 points over Labour, but did not have an overall majority at all.” UK Polling Report Anthony Wells of YouGov
To this disadvantage can be added the evidence that ballot rigging on a large scale is taking place in constituencies with large populations of Asians whose ancestry lies in the Indian subscontinent. As these Asian voters are much more likely to vote Labour than for the Tories, this also buttresses Labour’s likely 2015 electoral performance.
All of this points to a hung House of Commons after 2015. The chances of the Tory Party forming another coalition even if they are the largest party is much less than it was after the 2010 election. There are 650 seats in the Commons. After the 2010 election the Tories had 306, Labour 258 and the LibDems 57 seats. This provided a clear opportunity for the Tories to take a coalition partner which would create a government with a working majority. This situation is unlikely to be repeated. The LibDems, polling 6% in the latest IpsosMori poll, will almost certainly be reduced to something approaching insignificance , perhaps 20 seats or less. Even if they were willing to form another coalition with the Tories, on the present polling figures they would be unlikely to have sufficient seats to form another working majority Tory/LibDem coalition.
The temptation for Miliband to make a coalition with the SNP is great, but it would almost certainly deal Labour a mortal blow and finish it as a major party within two Parliaments . That is because Miliband would not only have to deny England English votes for English laws, but would be forced as a condition for SNP support to give more and more powers to all the devolved assemblies because it would be politically impossible to deny the Welsh and Northern Irish extra powers if Scotland gets more. Such a coalition might also end up increasing the gap between the Treasury pro-rata funding of people in Scotland, Wales and Northern Ireland and the much lower figure in England.
As a consequence, Labour would rapidly be seen by the English as an unequivocally anti-English party, while the Tories would be forced to make a choice between tolerating the injustice of the situation on the spurious grounds that they did not want to have second class MPs in the Commons (English MPs already are second class MPs because of the devolved assemblies) and becoming the Party of and for England. In view of the growing English anger and the seeming impossibility of ever regaining sufficient representation in Scotland and Wales to be again a serious force there, the likelihood is that the Tories would become the de facto Party for England, even if they probably would not openly embrace the title.
In such a situation, Labour would find their vote in England diminishing. At the General Election after the 2015 they would probably suffer significant losses in England. At the same time they would not get any credit in Scotland and Wales for giving more devolved powers to those home countries. Rather, the message to Scots and Welsh electors would be elect even more SNP and Plaid Cymru MPs and you will get further favours from the Westminster Government. SNP support will be made even firmer and Labour support in Wales is likely to suffer the fate the same fate as it has in Scotland and move en masse to the Welsh nationalist Plaid Cymru.
This would leave Labour almost entirely dependent on England for its representation, an England which they would be incensing throughout their period of coalition government by refusing English votes for English laws and pandering to Scotland, Wales and Northern Ireland. The probable consequence of that would be much diminished Labour support in England at the General Election after the one in 2015 (2020 unless the fixed term for parliaments is abolished). That is likely to be the end of Labour as a major party because the total Commons seats outside England are only 117. Even if all were willing to support a coalition government to keep the Tories out of office (a wildly improbable proposition), Labour would need around 233 English seats to give such a coalition a working majority and 209 seats for a majority of one. A Labour Party which had greatly antagonised the English, as a coalition dependent on non-English seat MPs would inevitably do, is unlikely to be able to muster anywhere near 200 English seats let alone enough for a working majority (In the 2010 election Labour only managed 191 English seats).
What applies to a Labour/SNP coalition would also generally apply to a rainbow coalition. The only significant differences would be (1) a larger number of parties in a coalition makes for a less durable and coherent government and (2) more parties which put up candidates in English seats would become toxic for much of the English electorate.