FOR the best part of two decades, the SNP’s leaders have been towering figures who dominated Scottish politics.

And there’s little doubt that their leadership alone played a central role in the party’s electoral success.

I’m not convinced people have fully processed Nicola Sturgeon’s sudden resignation and what it might mean for the party and the cause of independence.

Others have already pointed out that the cause is much bigger than any one individual, but it’s also true that a leader can make or break a political party.

I voted SNP for the first time in 2007, I was a student and about to graduate. I remember picking up an SNP leaflet on a bus in Glasgow on my way back from visiting my grandad in hospital – “It’s time”, it said, with a picture of Alex Salmond and Nicola.

Was it the partnership that appealed to me? The policy on tuition fees? Their ambition for Scotland in Europe? Most certainly all of those things. Their brand resonated, it was progressive, aspirational and they both spoke to different parts of Scotland.

For decades now, UK politics has shifted towards a presidential-like political system where party leaders carry most of the burden and the media intrude heavily on their private lives.

That’s not going to change before we re-design an alternative political system with independence – so if we want to stay competitive, we need a leader who can deliver, resonate and whose values we can trust.

Which is why the SNP now must put all of its energy into choosing its new leadership. This is a make or break moment for the independence movement and I don’t say so lightly.

Parties with great policies but whose leaders are out of touch rarely win elections – and unless we’re in government, we can’t deliver independence.

Politicians like Nicola Sturgeon come round once in a generation. But it’s her left of centre, progressive politics and her drive to fight poverty and inequality that will define her time in office.

A champion for equality, an advocate for climate justice, an internationalist. It’s those values that the party must firmly grasp as we search for our next leader.

Let me be clear – any lurch to the right, even by an inch, be it on social issues or the economy, would set us back. In a cost of living crisis where Labour are polling 20 points ahead of the Tories and a General Election is looming next year, the SNP must remain firmly left of centre – left of UK Labour and socially liberal.

For those with short memories, the SNP were not always in this space – indeed, we fought hard over many years to become the progressive party we are today – and that’s where we must remain – as John Swinney put it – the party of mainstream Scotland.

I’ve seen calls this week for the next SNP leader to focus purely on strategy – but leadership is more than that. It’s what you transmit to the nation that matters – an ability to connect with people, to show empathy and understand their struggles and their everyday lives.

So now that nominations have opened, I hope to see a wide spectrum of candidates come forward – including candidates with solid social justice credentials, given the economic crisis we’re currently facing.

A leader’s personal beliefs and values matter because they have a direct bearing on society. Of course, it is entirely possible to separate personal beliefs from the role of policy-making – Joe Biden, for instance, is Roman Catholic and champions abortion and the rights of women.

But any leadership hopeful with rigorous religious beliefs would need to give clear and emphatic asurances that those beliefs wouldn’t influence their policy direction and that they’d legislate for the whole country rather than the interests of a few. If they did so, they could secure wider consensus.

Because, make no mistake, in the months ahead, there will be no shortage of so-called conscience issues that the Scottish Government will have to engage on – from gender recognition to assisted dying, from buffer zone legislation to sex workers’ rights. A leader of a progressive party should champion every one of those issues.

I have no doubt that the forthcoming leadership contest will reinvigorate and breathe new life into the cause of independence. It’s an opportunity for the SNP membership to be front and centre of that process and play a full part in it.

And it’s an opportunity to hear directly from each candidate about their vision for Scotland and how to secure independence.

It’s clear to me that the “de facto referendum” as spelled out in the NEC resolution is now redundant. Setting ourselves a target of achieving 50% of the vote in a UK election with a brand new leader who is yet to build up a national profile is a risk too far.

But I do support using the next General Election as a single-issue election on independence where our target is to win a majority of seats and our goal is to negotiate for a transfer of power to enable a referendum. And if that fails, we should consider the option of convening a Constitutional Convention ahead of the next Holyrood election.

BUT if we are to pursue a single-issue election next year, two things need to happen as a matter of urgency. Firstly, by the end of this summer, following our Special Conference, and in partnership with other parts of the Yes movement, the SNP should establish, resource and mobilise a nation-wide grassroots Yes campaign in support of independence and in defence of Scottish democracy, with the explicit aim of growing public support for independence to well beyond 50%.

And secondly, a full prospectus for independence should be published, by the end of this year, setting out an alternative future as an independent country, laying out a strategy for economic prosperity, investment in public services and Scotland’s newfound role in Europe.

There is no amount of accusing Westminster of reckless mismanagement and corruption that will shift the dial – people need to understand what our alternative offer is.

The reality is that we haven’t refreshed our independence prospectus since the White Paper of 2013. That must change, and I’ll be looking out for candidates who prioritise this early on.

What struck me from Nicola’s resignation speech this week was her account of the intensity and brutality of politics in the modern digital world.

Our goal is not simply to achieve independence but to re-build a nation – one that is a little less polarised, more united and founded on kindness and respect. It will take all of us to achieve, and make no mistake – whoever succeeds Nicola will need our full support.