When Ed Miliband goes to Scotland and declares that ‘It is Labour that’s got to win this referendum’ it is a statement of political reality as much as it is braggadocio. The Tories have only one MP north of the border and the Liberal Democrats are the fourth party in the Scottish parliament. If this vote is to be won, Labour—as by far the largest Unionist party—will have to get the No camp over the line.

Ed Miliband’s decision to take the entire shadow Cabinet to Glasgow last week was meant to show that UK Labour is now engaging fully in this battle. Miliband himself thinks that he has come up with an argument for the Union that is distinctly Labour. It is that an independent Scotland would, as Alex Salmond’s commitment to a 3p cut in corporation tax shows, end up engaging in tax competition with the rump of the United Kingdom over who could offer the lowest rates to businesses and the wealthy.

Now, if you’re on the centre-right of politics this might not seem like such a bad thing. But this idea is anathema to the left and that is the sentiment that Miliband wants to connect with. He wants the cause of the Union to be the cause of social justice.

One consequence of Miliband’s position is that devo-max is off the table. He was quite clear to me that he would not agree to any devolution deal that encouraged the Scots to undercut the rest of the UK on tax.

Watching Miliband in Scotland on Friday, I was struck by how passionate he was about this argument and the Union. It is, obviously, in Labour’s interests to keep Scotland in the UK—Scottish MPs could well be the difference between Miliband becoming Prime Minister or not. But Miliband’s desire to win this referendum does seem to go beyond party politics. As he put it to me, ‘I don’t want my kids to think this is a foreign country’.

To date, the Unionist campaign in Scotland has been too negative and has suffered from an enthusiasm deficit compared to the Nationalists. The challenge for Miliband is to turn both of those things around.

Tags: Alex Salmond, Ed Miliband, Labour, Scotland, Scottish independence referendum, SNP, UK politics, Unionism. Scottish Independence