THE Foreign Secretary has threatened to withdraw assistance from the Foreign Office when SNP ministers travel abroad. 

It comes after a row erupted earlier this year when James Cleverly told senior officials across the globe to “confidently” represent “the strengths of the Union” amid fears the SNP were successfully using diplomacy with foreign governments “to promote Scottish separatism”.

Cleverly issued a set of rules to UK diplomats, including telling them to ensure that a UK Government official sits in on any and all meetings between SNP ministers and foreign governments.

In a letter to the Scottish Government first reported by The Telegraph, Cleverley said he was disappointed that the First Minister prevented one of his officials from sitting in for talks with Katrín Jakobsdóttir, the Icelandic prime minister, during his visit to New York last month.

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Cleverly reiterated that the guidance to have a senior official from the Foreign Office was `” longstanding” and was to ensure a “coherent and consistent message to our international partners”.

He added that if this continued, he would instruct his officials “to withdraw from facilitating meetings between Scottish government ministers and ministers of foreign governments”.

The SNP have slammed the Foreign Office's "desperate attempts to control and manipulate valuable discussions overseas" undertaken by the Scottish Government.  

SNP ministers are scheduled to make eight more foreign trips this year, including visits by Yousaf to Dubai in the UAE and Delhi in India.

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Previously, Dr Kirsty Hughes, a fellow of the Royal Society of Edinburgh who formerly worked at the European Commission, told The National that diplomats would most likely “ignore” Cleverly’s instructions.

She said: “These are serious politicians and diplomats and officials. They don’t need a desperately controlling – embarrassing frankly – message. I’m sure diplomats on the whole may well ignore [it].”

SNP MP Chris Law, who has been campaigning for the Scottish Government's right to meet with foreign ministers, said: "The Foreign Secretary claims that he wants a co-ordinated and coherent approach to international engagement – it is increasingly clear that this means it's either the Tory way or no way at all. 

“Earlier this year I was assured by the UK Government that their guidance would not restrict the Scottish Government’s ability to engage with governments overseas on devolved areas, but desperate attempts to control and manipulate valuable discussions overseas are precisely this. 

“In this case, our First Minister was joining the discussion at Climate Week in New York, showing how Scotland’s world-leading actions on climate change have given a path for others to follow.

"It is no surprise that the Tories would wish to shut this kind of discussion down, given that simultaneously Rishi Sunak was walking back their own net-zero targets. 

“It is increasingly clear that to protect Scotland’s international voice we need independence – these threats prove why next year’s General Election will be so important for the future of our country.” 

The Constitution and External Affairs Secretary Angus Robertson also previously insisted that April’s guidance “seeks to address a problem that does not exist” and claimed its real intention was to “censor” SNP ministers.

A Scottish government spokesman said: “We have received the Foreign Secretary’s letter and will respond in due course.”