The UK should have an extra bank holiday whenever one of the home nations' football teams reaches the final of the World Cup, the shadow foreign secretary has said.
Emily Thornberry was famously sacked from the Labour front bench in 2014 for a tweet apparently sneering at a white van driver's display of the cross of St George on his house months after the last World Cup.
But she sought to repair relations with the nation's fans by offering the prospect of a day off to nurse hangovers the morning after an appearance by England, Scotland, Wales or Northern Ireland in the final game of the tournament.
And she called on the Royal Mail to "reconsider" its decision to ban postmen from flying the flag on their vans.
She admitted she was not herself a fan of the game - and proved her point by going on to suggest the World Cup came round "every five years" - but insisted she did not think there was anything wrong with supporters displaying the flag.
"I think one of the things about the World Cup is that we do get lots of flags out and I think that there's nothing wrong with that," she said.
"If it's true, these reports we are hearing from the Royal Mail, I do hope that they reconsider because I think that there is no problem with this at all. This is a time for us to celebrate."
Ms Thornberry's comments came at a speech to journalists at a Westminster lunch, where she was greeted with a display of England flags laid on by reporters who were not about to let her forget the biggest gaffe of her political career.
But a smiling Islington South MP took the joke on the chin, telling reporters that in her north London constituency there were all sorts of flags on show during the World Cup.
"I can't pretend that I have the greatest interest in football, and I suspect that there's quite a lot of people like that," she said.
"But I tell you how you could get more interest in football. What about if the Government were to suggest, for example, that if one of the nations of the United Kingdom were to get into the finals... the next day will be a bank holiday?
"Why don't we do that every five years and that would help to get everybody behind whichever team it was?"
Ms Thornberry branded Theresa May a serial liar as she issued an impassioned plea for more honesty in politics.
She said she would personally be ready to take TV presenter Richard Madeley's "three strikes and you're out" challenge of having an interview shut down if she did not give a straight answer - as happened to Defence Secretary Gavin Williamson last month.
Ms Thornberry said there had been an "increasing normalisation of dishonesty in modern politics", citing the rise of US President Donald Trump as a sign that even the most senior politicians are now ready to say things they know to be untrue.
"This normalisation of dishonesty has also crept into all sides of British politics, in part I believe as a result of the debate around Brexit," she said.
She named the European Research Group of Tory backbenchers and the pro-EU Back Together group of MPs, who she said were each engaged in "earnest debate" about how to get the best Brexit deal, when in fact one side wanted no deal and the other did not want to leave the EU at all.
And she added: "Just look at the Prime Minister who, in the space of one interview last Sunday, claimed that she would fund a £20 billion boost on NHS spending primarily through the 'Brexit dividend'.
"She claimed that the Brexit transitional period would definitely finish at the end of 2020. She claimed that she had not misled Dominic Grieve and Anna Soubry on the `meaningful vote' amendment.
"And after all that she had the sheer chutzpah to say - and I quote - that she is a woman of her word."
Ms Thornberry said: "When it comes to what Jeremy (Corbyn) has called straight-talking honest politics and the kind of approach I've outlined today, that does mean setting your standards high.
"And, yes, it means we will fail those standards from time to time and we will be criticised and mocked as a result. But I would far rather that than having no standards at all.
Answering questions from Westminster journalists, Ms Thornberry declined three times to discuss allegations that Labour general secretary Jennie Formby was previously a member of Militant, insisting she did not know if that was the case.
And said she had smoked cannabis "a long time ago", but no longer thought it should be legalised for recreational use.