On a campaign stop in Stirling today, Sajid Javid, the Chancellor of the Exchequor, said it was "hugely important we have a system that works for the UK as a whole".
While Scotland’s population currently stands at a record high of 5.44 million, SNP ministers believe the figure could soon drop if immigration is cut post-Brexit.
All of Scotland’s population growth over the next 25 years – including the working age population - is projected to come from migration. The number of working age adults north of the Border is set to fall by 7,000 by 2043 while life expectancy is projected to increase.
A recent estimate by the National Records of Scotland suggests there will be 240,000 more pensioners by 2043 - a 23.2 per cent increase.
The SNP election manifesto launched this week claimed that "UK immigration policies do not take into account Scotland's unique circumstances and they are harmful to our communities and future prosperity". The party wants migration powers devolved to Holyrood.
Asked by The Scotsman if he accepted there was an economic case for such a move, Mr Javid said: "I don't accept the case for the devolution of migration powers. Having a system where the UK sets the rules is the right way forward.
"It is hugely important we have a system that works for the UK as a whole.
"So many sectors - the farming community, the fishing community - we need to make to sure they have the workers they need, and many of them do come from abroad. That's one of the reasons we said we would quadruple the seasonal agricultural workers' scheme.
"We will always be listening to Scotland's needs, and the needs of the UK as a whole, when it comes to setting any kind of salary threshold.
"If you look at the Border towns - I was in Berwick yesterday - it is hugely important that we don't end up with artificial barriers. And that's what a devolved immigration system would do."
A 2018 UK Government-commissioned report found that Scotland’s economic situation did not justify having a migration policy different to the rest of the UK.
The Migration Advisory Committee’s (MAC) study of immigration under EU free movement rules said Scotland’s economy did not need a “very different” migration regime to meet its labour requirements. The report said any changes by devolved administrations would be a “political decision”, not economic.
Stuart McDonald, the SNP’s candidate for the Cumbernauld, Kilsyth and Kirkintilloch East constituency, said: “Even the Tories now admit that their one-size-fits-all approach doesn’t work for Scotland.
“The Tory approach to immigration - ripping us out of the EU and imposing a ‘hostile environment’ - poses enormous risks to our economy and our public services.
“Ultimately, Scotland should make these decisions for ourselves - putting our values and economic interest at heart of our immigration system.
“We need to escape Brexit and put Scotland’s future in Scotland’s hands - not Boris Johnson’s.”