© Provided by The GuardianPhotograph: Leon Neal/PA
Keir Starmer has attacked the SNP for focusing on the "wrong debate" by demanding Scottish independence, but conceded the UK must "change to survive", as Labour gears up for the May elections.
The Labour leader was launching his campaign for what the party expects to be a tough set of elections to the Scottish and Welsh parliaments, and English councils.
Labour has often previously run completely separate campaigns in Scotland; but Starmer is keen to stress that Labour is focused on the NHS, jobs and growth throughout the UK.
The new Scottish Labour leader, Anas Sarwar, appeared at the online launch event, as did the Welsh first minister, Mark Drakeford.
Asked about recent comments from Drakeford that the UK "is over", Starmer agreed that it was time for constitutional change.
"I believe in the United Kingdom and what Mark Drakeford was saying was that he believes in the United Kingdom, but he recognises it's got to change to survive. And he's right about that," he said.
© Photograph: Leon Neal/PAThe Labour leader was launching his campaign for what the party expects to be a tough set of elections to the Scottish and Welsh parliaments, and English councils
"If the debate anywhere, particularly Scotland, is simply between the status quo and independence, then it's the wrong debate.
"I absolutely want to make a passionate case for the United Kingdom, and a socially just Scotland in a modern United Kingdom. And that's the message we'll be carrying to the voters in Scotland this May."
Starmer recently asked former Labour prime minister Gordon Brown to chair a constitutional commission, which will examine the status of Scotland and Wales, as well as the case for more English devolution.
Brown has previously promoted federalism - with sweeping new powers for Holyrood - as the best response to the pressure for independence and the uncertainty unleashed by Brexit.
In his speech at the launch event, Sarwar said, "I don't think it's credible for us to come through this collective trauma and go back to the old arguments. Arguing with each other while our NHS loses out on funding. Arguing with each other while our businesses close down and children miss out on vital education.
"And therefore I want people to know that the Scottish Labour party is on their side. It's on their side on the issues that matter to them.
Labour, then under Jeremy Corbyn's leadership, was pushed into third place in the 2016 Holyrood elections by the Conservatives, and hopes to regain some of that ground in May.
The party has been buoyed by several recent polls suggesting that support for independence is slipping modestly, and the public falling-out between Alex Salmond and Nicola Sturgeon may have dented SNP support.
A YouGov poll for the Times on Thursday suggested 36% of voters think there should be a referendum on Scottish independence this year if the SNP wins a majority at Holyrood - down from 43% last November.
Support for independence itself slipped to 49%, from 51% in November. A separate poll for the Scotsman this week suggested the SNP could miss out on a majority in May's elections, which were delayed last year because of the pandemic.
In Westminster, Boris Johnson's government is devoting an increasing amount of political energy to trying to undermine the case for Scottish independence, including by highlighting the success of the vaccine programme as a cross-UK endeavour.
The prime minister reportedly told a recent meeting of backbench Tory MPs that without the union, "the SNP government in Scotland would not have a single vaccine for the Scottish people".
As well as the Scottish parliament and Welsh assembly, there will be elections to many local councils in England on 6 May, as well as a string of mayoralities, including the West Midlands, Manchester and Teesside.
Labour is playing down hopes of making gains, but many in the party will see the results as a test of Starmer's progress in rebuilding the party's support after the 2019 general election defeat.
The Electoral Commission has published new guidance on Thursday about how the elections can be conducted.
Candidates will be allowed to knock on doors or deliver campaign leaflets, as long as they give their party's pitch from 2 metres away, and not go inside.
They will also be able to offer masks and hand sanitiser to people as a way to encourage them to turn out to vote - but only if this is "to assist voters generally", and not to encourage them to vote a certain way, an offence known as "treating".
If masks or bottles of sanitiser carry a party logo or slogan, they must then also then have the small print that is seen on election leaflets, stating who has paid for it.
Also, someone wearing a party-logo mask might be asked to change it if they wear it to a polling station, as campaign items are not allowed there.
Finally, if parties do decide they want to hand out masks or sanitiser, this counts as election spending, and must be included on their spending return.