What does Nicola Sturgeon want in return for supporting a Labour government?

It’s four-wheel-drive or no deal, guys. Andrew Milligan/PA

Ed Miliband has emphatically stated that he would not form a coalition with the SNP in the event of a hung parliament on May 7. But Nicola Sturgeon is equally adamant that Miliband may have no choice but to take her party’s support if it wants to hold on to power.

Miliband may find himself in a situation where his only chance of becoming Prime Minister depends on obtaining the support of Scottish nationalist MPs, at least on a case-by-case basis for parliamentary votes. And if that happens, certain issues are more likely than others to appear on the negotiating table.

While the two work out whether they can stomach working together in order to keep the Conservatives out of government, it’s worth considering which issues would matter most to Sturgeon if she did hold the balance of power.

Devolution

The first is, of course, handing more power to the Scottish Parliament. Labour’s manifesto contains a commitment to ceding more control on tax, welfare and jobs, and the SNP is keen to push for “devo max”, including full fiscal autonomy. Labour has opposed this last wish, but some kind of agreement on further powers could be possible. The SNP could then claim that their newly large contingent of Westminster MPs is bringing results for Scotland, while such a deal may not involve any particular u-turn in Labour’s current position.

The West Lothian question

In the past, the SNP has generally resisted voting on laws that only affect England. But Nicola Sturgeon has signalled a shift in this position, arguing that what happens in England on matters such as health can have knock-on budgetary consequences for Scotland.

The extent of co-operation between Labour and the SNP may partly depend on how elastic Sturgeon is willing to be in voting on matters that mainly affect other parts of the UK. Miliband will know that if nationalist votes prove crucial to Labour pushing through controversial reforms affecting England, the Conservatives and UKIP are sure to exploit the issue.

Trident

The SNP is implacably opposed to having nuclear weapons in Scotland, and its anti-nuclear stance is a core commitment for many of its members.

Labour could probably rely on Conservative votes to pass legislation to renew trident, but a key question would be how much the SNP would seek to punish this move by withholding support from Labour in other votes.

Austerity

The SNP rejects the view that deep spending cuts will be needed during the next parliament, and would hope to find allies on the Labour backbenches to oppose them. This issue could prove a particular problem for cooperation between the parties, as the SNP will be extremely reticent about voting for unpopular cuts.

Grudge match. Stefan Rousseau/PA

But this is also not a clear-cut issue. Although Sturgeon’s opposition to austerity has won many admirers across the UK, she has also acknowledged the need for debt reduction. As yet we only have sketchy idea of how Labour would approach this problem so there would be plenty scope for post-election discussions on spending.

Social democracy

Whisper it, but Labour and SNP members often have similar values and goals – even if the idea that the SNP and Labour could be considered natural coalition bedfellows amuses many familiar with the tribalism of Scottish politics.

There is long-standing enmity between the parties and Labour is currently facing the prospect of being electorally routed in Scotland by the SNP. Meanwhile, the nationalists are still angry that senior Labour figures worked to defeat the Yes campaign in the 2014 independence referendum.

Yet both Miliband and Sturgeon are seen by some as having moved their parties in a more social democratic direction. Miliband has pledged to increase the top-rate of taxation and to impose a mansion tax and Sturgeon has quietly dropped Alex Salmond’s flagship policy of reducing corporation tax – a proposal that had been unpopular with many on the left.

We can work it out

If SNP support for Labour were provided on a vote-by-vote basis, they may find that their instincts on many issues are similar, at least enough so to make policy agreements achievable.

Co-operation can bring major risks for political parties. Electorally, the Liberal Democrats have paid a heavy price for coalition with the Conservatives. Meanwhile, Scottish Labour has suffered for its partnership with the Conservatives in the Better Together campaign against independence.

These examples many serve to make parties even more cautious of being seen to work closely with rivals in the event of a hung parliament. Yet both Miliband and the SNP may find themselves in a post-election situation in which they have a one-off opportunity to make inroads. Informal, case-by-case voting agreements could be the best arrangement for both.