In truth, I’ve been wrestling with this piece for more than a week now. Three times I’ve picked it up and put it down. Sometimes, it’s hard to see the wood for the trees, to be able to pluck the analysis from the swirl of detail and politics. Headspace for thinking is sometimes hard to find.

But two very important thought pieces in Scotland on Sunday today helped crystallise the nub of what I’m about to say. Must-reading for everyone in Scottish politics, frankly: first, Duncan Hamilton sets out how three events this week have shown how Labour’s political influence in Scotland is plummeting still and second, Kenny Farquharson details how the SNP is engaged in a cultural revolution encouraging its supporters and indeed, Scots to embrace their inner Britishness. As an unreconstructed Nat, it makes for discomfiting if thought-provoking reading.

Both articles, to some extent, provide context for my assertion that one of the key independence battlegrounds is in England and specifically, over the NHS bill.

The most important speech in Scottish politics over the last few weeks wasn’t actually made at a party conference but by Depute First Minister, Nicola Sturgeon in a lecture at Glasgow University. Here was a senior SNP figure beginning the process of laying out what independence is for and highlighting key differentials between “there” and “here”. The NHS and its treatment was key, so key, in fact, that it featured in not just her address to the SNP Spring Conference a week later, but in all the major speeches of the weekend.

The Cabinet Secretary for Health asserted that independence was but a vehicle to a fairer Scotland and that the biggest threat to the welfare state – the quintessential British construct – was the current UK Government. “Independence will give Scotland the opportunity to make different decisions and to implement policies designed for its own needs in every area. In welfare as well as health, the economy as well as education. In the past the union would have been seen as not just the creator but also the guarantor of the values and vision of the post-war welfare state. Today, many see that it is the union, under the Westminster government, that poses the biggest threat to these values and that vision.”

Both she and the First Minister laid out in their Spring conference speeches quite deliberately and clearly that the little amount of independence we have currently – an interesting take on the devolution settlement which was largely ignored by the mainstream media – enables Scotland to choose a different path over the NHS. In essence, there will be no privatisation of the NHS in Scotland under the watch of an SNP Government.

Whatever the detail of the NHS bill currently causing such storm and fury south of the border – and it is hard to keep up with the convolution of its measures amidst the spin and counter-spin – we in Scotland are looking from afar at the Conservatives doing what we always suspected them of doing – of dismantling that which we hold dear – the idea of an NHS in public hands, free at the point of need.

For sure, the Liberal Democrat membership tried to stymie their leadership’s complicity in the deal, but they failed. Despite a refusal to back the bill at the party’s UK Spring Conference, their MPs and Lords are holding fast to their commitment (largely) to coalition government and supporting it. Meanwhile, Labour is doing a grand job of leading the charge under Andy Burnham, whom most commentators agree is playing a blinder, but it will come to nought. As Duncan Hamilton points out: “politics is about power, and Labour has none”.

Especially here in Scotland, which enables the SNP to drive a further nail in Labour’s coffin. One of the other interesting themes of the First Minister’s speech in particular, was that only the SNP can protect Scotland’s interests against the worst perfidy of a Tory-led government at Westminster. Whereas Iain Gray tried to make this concept stick during the 2011 Scottish election campaign and failed, the SNP can state it with greater authority. Because the SNP has the power and the backing of the Scottish people to do so.

Hence, the clever tactical focus on measures like the NHS bill which point this reality up and which enable the SNP to make the positive case for independence.

Clearly Nicola Sturgeon and Alex Salmond – and the unseen army of often brilliant party tacticians and strategists – have a nose for these things and have determined to capitalise on the coalition’s woes. The Scottish Government will wring every last drop of political advantage from the situation unfolding south of the border.

Tom Gordon at the Sunday Herald erroneously portrayed the core of the First Minister’s speech to conference as an attempt to pitch the referendum as a personality contest between himself and David Cameron. He’s wrong: the messaging here is much more potent and heady, more complex and far more fundamental than that. It’s about appealing to values held dear, and nothing is held in greater esteem by Scots than the NHS. In any poll, health is always top or nearly so; indeed, clinging to the notion of a universal, entirely public NHS exposes Scots’ innate conservatism (as Alex Massie pointed out).

The Massie one also beat me to the observation that there is an irony inherent in the SNP – the party which wants to change the rules of the political game forever – aiming to do so by changing not very much at all.

But the politics has a purpose. They privatise, we protect. They ignore, we listen. They dismantle, we build. If devo-whatever is Ruth Davidson’s line in the sand, then the NHS could become a symbolic no passeran, one for which the Scottish public might well take to the barricades, or at least to their ballot papers.

The SNP’s instincts on this are spot-on. Claiming to protect the NHS with the little independence we have, and articulating the idea that real independence would deliver the health service we want; laying claim to be the real defender of a tenet of Britishness which is safer if Scotland goes it alone; these are the kind of arguments which will make Scots pause and think.

And persuade many to realise that a yes vote might deliver the change – no change at all, in fact – they wish.