Dividing lines. Now, where have we heard that before?
Gordon Brown loved them. George Osborne relished them. In an era that had been dominated by centre ground politics where everyone fought over the middle, those lines were important to answer voters' claims that "they're all the same".
Today, Labour is spelling out "dividing lines" for a different reason.
For months the party has agonised over its position on Brexit. Wrangling with four seemingly incompatible truths - millions of their voters in traditional Labour areas wanted Brexit; the vast majority of the party's MPs wanted to stay, in line with its official position; the leader was Remain but not exactly in love with the idea, but an important constituency of Labour voters at the New Labour end of things were ardent Remainers.
In the end, Labour concluded it had to back the government's triggering of Article 50 with a few notable exceptions. And now it has officially backed Brexit. How, on this issue, can they show they are different to the Tories?
Enter Sir Keir Starmer's speech this morning, interestingly, well ahead of the party's manifesto.
He'll promise Labour would guarantee rights for EU nationals who live in the UK, sources say a '9am, day one' action for a Labour government.
He'll say Labour would scrap the Tories' Brexit plan and in its place put forward legislation that would more fulsomely and explicitly protect all rights currently enshrined in European legislation. He'll say the idea of walking away with no deal must not be an option, and give Parliament a say on the final deal as well as regular formal updates.
It is very different to the Tory plan and there has been a very active campaign to protect EU citizens who live in the UK.
And a second referendum will not be in the party's manifesto. Labour will hope not to get bogged down in arguments over that.
Privately senior figures say it's not possible to see how you get to a second vote, logistically or politically.
But on the fairly understandable basis that in 2017 politics it is foolish to rule absolutely anything out, they can't or won't say explicitly say that under no circumstances could there ever be a second vote, or under no circumstances could we ever stay in.
A senior source told me they would never argue to stay in the EU as it is, but IF there were significant reforms that situation could hypothetically change. It is a massive IF, even worth putting in capital letters in bold!
For some of their voters, particularly in London, that's the kind of approach they crave.
But claims from their critics that Labour could potentially seek to stay in the EU is a dividing line the party hardly needs.