First Minister Nicola Sturgeon will take the campaign for independence to the United States this week as the stand-off between Holyrood and Westminster over the constitutional future of Scotland in the wake of Brexit intensifies.

The SNP leader will discuss the issue of independence in a speech - entitled “Scotland’s place in the world” - to an audience at the prestigious Stanford University in California. She will also focus on her party’s opposition to Brexit. Sturgeon will also speak at the United Nations on the issue of support for women in conflict and sign a joint agreement with the Governor of California on climate change. Despite raising independence during her US trip, the First Minister’s America visit will mostly focus on trade and investment.

It is understood that no meetings with officials in the Trump administration are scheduled. However, Sturgeon's key meeting on climate change is likely to be seen as a pointed rebuttal of Trump and his policies.

Tory MSP Annie Wells criticised the planned talk: “The First Minister seems determined to talk about independence at every opportunity she gets. Rather than going abroad to try and sell her plans for separation, she should accept that Scots don’t want a second independence referendum and get back to the day job of improving our health service and schools.”

The Scottish and UK Governments are at loggerheads over Sturgeon’s call for a second independence referendum in response to Scotland voting overwhelmingly to remain in the European Union. Sturgeon wrote to Theresa May last week to formally request a second Scottish independence referendum after MSPs voted 69 to 59 in favour of seeking permission for a vote to take place between autumn 2018 and spring 2019. However, the UK Prime Minister has said that ‘now is not the time’ for a second plebiscite. Although May has not officially rejected the request in writing, sources expect her position to be formalised within a matter of days.

In the meantime, Sturgeon is expected to try to improve the case for independence and attempt to win over public opinion ahead of an expected referendum in the medium term.

In her first overseas trip since Holyrood backed ‘Section 30’ talks with the UK Government, Sturgeon will visit New York and California in a bid to boost trade and investment. However, the trip will also have a sharp political edge.

On Tuesday, she is due to address academics and students at Stanford University in California, one of the world’s leading research and teaching institutions.

A preview on the University website states: “Scotland’s First Minister Nicola Sturgeon will discuss key international issues affecting Scottish, UK and international politics. She will touch on a range of areas including Brexit, climate change, refugees and Syria and the relationship between the US and Scotland.” A senior Scottish Government source said: “The Stanford speech will focus both on Scotland’s current position, considering Brexit and independence, some of the reasons why voters in Scotland may have voted against Brexit and lessons that can be learned, but also global challenges around climate and refugees.”

The speech will inevitably be seen as Sturgeon trying to position herself as an international stateswoman who is trying to sell independence to a US audience as part of a planned charm offensive. In the first independence referendum, President Obama strongly indicated that he favoured a No vote in an eleventh hour intervention.

“The UK is an extraordinary partner for America and a force for good in an unstable world. I hope it remains strong, robust and united,” he wrote.

His successor, President Trump, has yet to make any comment about Scottish independence in office.

However, Obama was opposed to the UK leaving the EU, unlike Trump who welcomed Brexit.

Sturgeon said last week: “Following the UK’s vote to leave the EU and the UK Government’s decision to leave the single market, I want to reassure investors and visitors from the United States that Scotland is an outward looking, welcoming country and remains open for business. I look forward to building on the existing links between our countries and promoting Scotland as a country to invest in, visit and live.”

Paul Cairney, a Professor of Politics and Public Policy at Stirling University, said of the trip: “These events tend to be set up well in advance, and they serve the wider purpose of ‘paradiplomacy’ in which Scottish ministers sell Scotland in various ways, from its commercial opportunities to its values. However, Nicola Sturgeon will know that, for the foreseeable future, people will be paying particular attention to her views on the implications of Brexit for the next Scottish independence referendum.

“The challenge will be to marry those two things together: to state how vibrant and welcoming Scotland is, and assert its right to self-determination, while also signalling the kind of caution and moderation required to make sure that Scotland does not look too unpredictable or chaotic.”

Phillips O’Brien, a Professor of Strategic Studies at St Andrews University, said: “Certainly one assumes that the Scottish Government would want to be seen as internationally engaged and state-like in its discussion about Brexit. It will be the pivotal issue in any second independence referendum, so they would want to get their message out.”

Labour MSP James Kelly said: “With Scotland’s economy lagging behind the rest of the UK, our NHS under unrelenting pressure and the gap between the richest and the rest in our classrooms as stubborn as ever, Nicola Sturgeon should be focused on governing and attracting investment when she is in America, not borrowing from Alex Salmond’s book on international grandstanding and rerunning the divisive arguments of the past about independence.”