Boris Johnson will visit Scotland on Thursday to try to stem support for independence, as ministers grapple with ways to persuade Scots of the advantages of remaining in the 313-year-old union with England.

The prime minister is expected to focus on the vaccination effort to highlight the role of the whole UK in what has so far been one of the world’s most successful Covid-19 inoculation programmes.

Meanwhile, ministers in London are looking to bypass the pro-independence Scottish National party government in Edinburgh by funding some “UK projects” north of the border directly from London.

But while Mr Johnson wants to remind Scotland that the UK Treasury has underpinned economic support packages during the coronavirus crisis, some ministers are uneasy at a strategy depicting Scots as recipients of cash from London.

Alister Jack, Scotland secretary, told Conservative MPs at a Burns night event on Monday that Scots should “feel valued as partners in a shared endeavour rather than just a recipient of UK largesse”, according to one person who was present.

Mr Jack reminded Tory MPs representing English constituencies of the role Scotland played in the economic and cultural life of the UK — from the Edinburgh festival to whisky exports and research into artificial intelligence.

One former Conservative cabinet minister criticised the government’s strategy for countering the SNP, saying: “I don’t think there has been a coherent strategy on the union.”

He added that the cabinet was split between those such as Cabinet Office minister Michael Gove, who wanted to work collaboratively with the devolved administrations, and others who sought a more “muscular” unionism. “I think that’s where a lot of Boris’s instincts are — the idea we should tell the Scots why the union is good for them,” said the former minister.

In his speech to the Scottish Tory conference in November, Mr Johnson suggested taking powers from the Edinburgh parliament and reallocating them to local authorities and communities.

Mr Johnson’s visit to Scotland comes after opinion polls over the past year have suggested that a majority of voters in a Scottish referendum would back independence.

A poll by Panelbase for The Sunday Times put support for independence on 49 per cent, with 44 per cent opposed and 7 per cent undecided.

The poll also found that only 22 per cent of Scots thought Mr Johnson has done a good job on Covid-19, compared with 61 per cent for Nicola Sturgeon, Scotland’s first minister.

Ms Sturgeon on Wednesday called on Mr Johnson to “lead by example” by refraining from unnecessary travel. The prime minister’s allies said his visit to Scotland would be Covid-secure, as with other events around the UK.

Some Conservative politicians hope that spending more money directly in Scotland — and badging resulting projects clearly with the union jack — will help build support for the UK government.

Legislation approved last year allows Westminster to bypass the devolved administrations in Scotland, Wales and Northern Ireland to spend funds on infrastructure, education, and any cultural and sporting activities that UK ministers judge will “directly or indirectly benefit the UK”.

The UK government already partly funds so-called city deals to support economic growth in Scotland, but does so in co-operation with Scottish ministers. Chancellor Rishi Sunak is also promoting a series of freeports across the UK, including in Scotland, that ministers hope will become hubs for high-value manufacturing and innovation.

Mr Gove, who is leading the fight in the cabinet to save the union, is focused on making the wider case for the UK and British identity, rather than devolving more powers to the Scottish parliament.

A review by Andrew Dunlop, former Scotland Office minister, into how to make the union function more effectively is lying on Mr Gove’s desk. Completed in November 2019, Mr Gove has promised to publish it soon.

Ms Sturgeon has vowed to try to hold a second referendum on independence if parties that favour it control the Scottish parliament after elections scheduled for May. Mr Johnson insists that UK approval is required for such a vote and that he will not give it.

Iain Anderson, executive chair of Cicero, a financial consultancy, and a former Tory adviser, said business was “increasingly taking an interest” in the future state of the union when making investment decisions.