Scenario one: An SNP-Labour Coalition
After Ed Miliband falls more than 30 seats short of an overall majority, the only way he can guarantee inheriting the keys to Downing Street is through a deal with the SNP.
The phalanx of Nationalist MPs abandon their party’s usual practice of abstaining on English-only laws to ensure the minority Labour administration gets its budget and legislation through the Commons.
In return, Nicola Sturgeon demands fresh and substantial devolution of powers to Holyrood. Her vehement opposition to the renewal of the Trident nuclear fleet on the Clyde provokes particular ill-will.
Meanwhile Tory MPs under their new leader, Boris Johnson, are in revolt over Labour pushing through policies in England for which it has no mandate.
They are emboldened by opinion polls underlining public anger south of the border over the arrangement, with Ukip, despite its disappointing election result, stirring the pot.
The evident resurgence of English nationalism, inflamed by aggressive coverage of the situation by many national newspapers, is pushing the two nations further apart.
North of the border, increasing numbers of Scots say the time is right to break away from the UK, arguing that it is only one small step to independence.
Scenario two: A Labour-Conservative 'National Unity Government
Once the shock-waves subside from the SNP’s stunning electoral performance, senior Conservative and Labour figures start thinking the unthinkable: a Westminster deal to keep the Nationalists from power.
It is an almighty upheaval for parties who have spent the past century in mortal combat, and the Labour Left and the Tory Right are livid. Conservative Eurosceptics are incensed they will not get their promised vote on leaving the European Union.
Some irreconcilables on both sides quit their party whip in protest, but the grand coalition still occupies more than 80 per cent of the Commons’ seats.
Work presses ahead on an overhaul of the UK’s constitutional arrangements, although it becomes bogged down in arcane detail, but the coalition partners struggle to find common ground, most notably over moves to tackle the deficit. The Chancellor Ed Balls is said to be barely on speaking terms with his Tory deputy Sajid Javid.
In Scotland, rebellion is growing as the SNP stoke up resentment over an English stitch-up to keep Scots from power. Support for separation is surging and demands for a new independence referendum mount.
The grand coalition collapses in bitterness and acrimony, with a new election held in 2017.Reuse content