Boris Johnson was accused of using the coronavirus pandemic “as some kind of political weapon” by Scotland’s first minister, Nicola Sturgeon, against a backdrop of rising tension over the future of the union. Sturgeon accused the prime minster of “celebrating” the pandemic after Johnson used his first visit to Scotland since last December’s election to hammer home his message that the UK’s response to the virus exemplified the “sheer might” of the union. He claimed it would have spelled economic disaster for Scotland had it not been able to rely on the UK Treasury for assistance. Describing the furlough scheme as a “fantastic demonstration of the way we work together as one country”, Johnson denied using the crisis to shore up diminishing support for the union, as polling shows a sustained majority in favour of Scottish independence for the first time. Johnson did not respond to questions about reported cabinet panic at growing support for independence, after it emerged on Wednesday that he had ordered senior ministers to visit Scotland more regularly and make their government more visible in the Scottish media. Resurrecting instead the lead slogan from the 2014 referendum’s pro-union campaign, he said: “I think the country is far better together and that’s what I believe in.” The relationship between the Westminster government and devolved administrations has become increasingly strained over the pandemic, as an initially unprecedented “four-nations” approach fell away, with groups charged with coordinating the inter-governmental response simply ceasing to meet by early May. A report published on Thursday by the Scottish affairs committee described a “vacuum” in ministerial-level communication between the UK and Scottish governments, and detailed how collaboration between the nations deteriorated as lockdown measures started to be eased. The Welsh first minister, Mark Drakeford, has complained that, despite giving himself the title “minister for the union”, Johnson has failed to speak to its component parts. Insisting he was not politicising the crisis, Johnson added: “It’s not a remotely political point, I just happen to think that’s the best way to do things and I think it’s a great thing for our country. “When you strip away some of the rhetoric, beneath it the UK is dealing with the crisis in a way that is very uniform across the whole of the country and we’re going to get through it together.” Despite sustained criticism from the Scottish Conservatives of Sturgeon’s more cautious approach to opening up the economy, most recently with the Scottish government advising office workers to continue to work from home while Johnson has encouraged them to return to workplaces, the prime minister said: “The unity and shared approach is much more significant than the differences.” Speaking to the media at a military base at Lossiemouth, on the north-east coast of Scotland, where a handful of pro-independence supporters were gathered at the gates, Johnson also denied avoiding Scottish voters, saying he met “loads of people” during his morning trip to Orkney and at the nearby Baxters Highland Village, who “seemed in a very good mood”. His brief appearances on Thursday are unlikely to diminish his chronic unpopularity in Scotland – recent polling for the Sunday Times put Sturgeon’s approval rating at three times that of the prime minister. Asked why he thought that Scots believed that her handling of the crisis has been so much better, Johnson again deflected the question, replying: “Whatever the superficial political differences and the differences in presentation, the reality is that this country is tackling the coronavirus crisis with much more that unites us than divides us.” At her lunchtime media briefing, Sturgeon was far more direct, telling reporters: “None of us should be crowing about this pandemic in a political sense.” She also rejected Johnson’s claim that an independent Scotland would not have had the financial muscle to stop coronavirus causing an economic disaster, adding that his claims about the might of the UK Treasury were really “just a feature of where power lies”. She went on: “If Scotland was an independent country then just like Ireland or many of the other small countries, we’d be doing these things ourselves. “I just don’t think any of us should be championing and celebrating a pandemic that has taken thousands of lives as some, you know, example of the pre-existing political case we want to make.” Asked on his visit whether two Conservative MPs on the intelligence and security committee, Theresa Villiers and Mark Pritchard, and others who had received donations from individuals or companies with Russian links should return the donations, Johnson said: “We have a rule that we don’t take foreign donations. But what I don’t like to see is people automatically assuming that everybody who is associated with some country or other is in some way untouchable. We are not a racist country.”