In an interview with Vogue magazine, Sturgeon claimed that though she tries to “find whatever common ground we can” when working with prime ministers, the approach “works better with some than others” – a seeming dig at Johnson.

Sturgeon thinks that the prime minister is delegating most of his interactions with the devolved governments to the Secretary of State for Housing and Communities Michael Gove, and suggested that the reason for doing so may be “just a bit of a fragile male ego.”

“That’s fine, Michael Gove and I work together well, but it’s a different approach to his predecessors,” she continued.

"He seems to have a disinclination to be, metaphorically speaking, in the same room as me. It's odd"

The COP26 UN Climate Change Conference is set to take place in Glasgow, Scotland from Sunday and will be attended by many world leaders, including US President Joe Biden, French President Emmanuel Macron, Turkish President Recep Tayyip Erdogan, Australian Prime Minister Scott Morrison, Israeli Prime Minister Naftali Bennett, and Canadian Prime Minister Justin Trudeau.

Johnson and Sturgeon will also be in attendance, though it is not clear whether they will speak directly with each other.

Two major world leaders – Russian President Vladimir Putin and Chinese President Xi Jinping – will not be taking part in the conference, though China will be sending a climate representative in Xi’s absence.

Tensions between Johnson and Sturgeon have heightened following the UK’s withdrawal from the European Union. Sturgeon has repeatedly threatened to launch another Scottish independence referendum, and has warned Johnson not to block such a move.

Johnson, on the other hand, has told Scottish nationalists to stop talking “endlessly about another referendum” while the UK attempts to fight the Covid-19 pandemic, and has called the concept of a second referendum – just seven years after the first – “reckless” and “irresponsible.”

In January, Sturgeon claimed the prime minister “fears the verdict and the will of the Scottish people,” and in 2019, she called Johnson “a complete and utter charlatan” who “only ever put his own interests first.”