Rachel Reeves must have been smarting this week as the new Chancellor stood on the steps of No 11 Downing Street - but she's now using her former platform to make a clarion call for Britain's re-entry into the European Union.
Her former rank carries weight and adds fuel to the prime minister's arguments on re-opening the EU debate.
That also opens up a Pandora's box of inter-twining constitutional questions here in Scotland.
The Reeves argument is clear. From her position in His Majesty's Treasury, she saw a United Kingdom that was "poorer, weaker and less secure" post-Brexit.
She therefore believes "Britain's future lies in the EU".
Her intervention may leave many people questioning - why make it now, after leaving office?
It has been up to the new prime minister to make the running, with Andy Burnham looking forward to an EU summit in Brussels on 20 November.
He's looking to lock-in deals on food and drink, emissions trading, and a youth mobility scheme.
It adds to the impression there has been almost seven years of the UK trying to patch things over with the EU, sector-by-sector.
Speaking on BBC Scotland's Sunday Show, the UK government minister Martyn McCluskey was asked when the people might be consulted about this?
He said: "I'm not going to get ahead of myself on process here. What we need to focus on is we're having a conversation.
"A conversation that was happening already in the country, that I think Andy Burnham has just said very clearly. It's a conversation we're all having, so we may as well have it in public about what the benefits are."
It's certainly clear that, after the summit, the prime minister wants to "explore options" for the longer-term relationship. But there will be no major changes before the next general election
All this rather horrifies the Conservatives.
Their leader Kemi Badenoch said on Sunday it was "yet another Westminster bubble argument".
Her Shadow Scottish Secretary Harriet Cross told the Sunday Show: "When we have a vote, that should be respected. That is the point of a democracy and it's incumbent on everybody to make that work and there have been benefits to leaving the EU".
What is particularly horrifying for the Conservative leadership is the prospect of re-opening the decades of Tory in-fighting on a matter they thought had been put to bed.
Far from horror, the SNP view the prime minister's European stance with some glee.
Brexit is so woven in with the issue of Scottish independence that it can be hard to unpick the threads.
The SNP's Westminster leader, Dave Doogan, told me he "really welcomed" Rachel Reeves' comments, and a majority of Scots had already known that leaving the EU was a "retrograde" step.
He said: "When you are sold a false prospectus, it's ok to go back to re-visit that after a reasonable period of time and I would say that, whilst that's appropriate for the European Union referendum, it's also appropriate for the referendum that happened two years prior to that in 2014 over Scottish independence."
The leader warned it would be "hypocrisy" not to re-visit the independence issue.
However, when the prime minister was in Glasgow on Friday, Downing Street was clear that a second independence referendum is "off the table".
It's unclear at this early stage what impact there could be on the SNP's "independence in Europe" argument if the UK does seek ever-closer union, or even re-joins the EU.
Given all these arguments, it is striking how often people outside the political bubble tell me they just want "certainty" over all these constitutional issues.
It's probably a very human reaction but their hope is maybe misplaced.
These arguments never really lie still.
For hundreds of years the relationship with our neighbours was fought in cross-border skirmishes or in battles across the English Channel.
Now, it's down to democratic votes and arguments in air-conditioned summit rooms.
With the prime minister re-opening this Pandora's Box, be prepared for plenty more constitutional debate.