Britain must axe “cruel” rules restricting chain migration so that families won’t be separated at Christmas, the Scottish government has claimed, demanding Westminster grant Holyrood powers to throw open the border.

Scotland’s open borders-backing immigration spokesman, Stuart McDonald, ordered Westminster to scrap income threshold requirements designed to ensure UK citizens seeking to import a spouse from abroad will be able to support their new family financially.

“Rather than being able to spend time with their families and loved ones around the Christmas dinner table, many people with foreign spouses will be forced yet again to spend the festive period communicating with families over Skype.

“Not only would that be a continuation of a devastating policy that has split an estimated 15,000 children from their parents, it would be a continuation of its hostile environment that is putting off people from coming to the UK and contributing economically and socially,” he told The National.

He added: “I have repeatedly pressed the Home Office to ditch these cruel anti-family policies and adopt an evidence-based approach that keeps families together, attracts talented workers and helps our economy and businesses grow.

“The Tories must either radically reform or scrap its disastrous family visa rules and wider immigration policy, or devolve the powers to Holyrood so we can implement a progressive policy that suits Scotland’s needs.”

While McDonald claims he wants to see an “evidence-based approach” to immigration policy, the Scottish National Party (SNP) minister has seemed reluctant to accept data which would contradict his party’s insistence that Scotland needs mass migration.

When Migration Advisory Committee (MAC) head Alan Manning gave evidence to the Commons Home Affairs Select Committee in October, after the body produced a report which showed how a decade of low-wage mass migration on the UK labour market had provided “no clear benefits” for citizens, McDonald said he welcomed the “fantastic research” by the organisation, but demanded it redraw its conclusions, which recommended Britain close its doors to low-skilled migrants.

Urged by the SNP spokesman to outline all the benefits to mass migration, the LSE labour economics professor stressed the phenomenon “hasn’t really had positive effects”, explaining that the overall outcome of adding more than a million low-paid migrants has been to shape Britain into a “lower wage, lower productivity kind of economy”.

The Scottish government has repeatedly called for immigration powers to be devolved after Brexit so that Holyrood can open the border, claiming that — without freedom of movement — the nation would lose £10 billion by 2040 — an SNP-produced figure which has been savaged by Migration Watch UK.

The migration policy watchdog noted that “what is categorised as a potential ‘cost’” in the report was “not based on a claim lower immigration would lead to an actual shrinkage in the economy, but an estimate that it could lead to a lower rate of future economic growth”.