AMBER Rudd's position as Home Secretary is "untenable" in the wake of the Government's "callous" treatment of the so-called Windrush generation, the SNP's leader at Westminster has said.

Ian Blackford MP is demanding the Home Secretary consider her position, as he called for Prime Minister Theresa May to "show leadership" over the controversy.

Describing the situation as a "disgrace", Blackford said: "Amber Rudd has failed in her responsibilities – she has shown the Home Office at its most incompetent and callous – and has undoubtedly damaged the UK's standing and reputation."

The issue centres around the treatment of Commonwealth citizens who arrived in the UK between the late 1940s and early 1970s and have recently found their migration status under challenge.

Recent restrictions in immigration law require people to have paperwork proof of near-continuous residence in the UK.

Many in the Windrush generation lack these records, having never applied for British citizenship or passports, and they are now struggling to prove they are here legally.

It has also emerged that thousands of landing card slips recording the arrival of Windrush-era immigrants were destroyed by the Home Office several years ago.

Blackford said: "The Windrush situation has been nothing short of a disgrace. That people who have lived here lawfully for up to 50 years were being told their presence in the UK was illegal says so much about the approach of this Tory government.

"It is now time for the Home Secretary who has presided over this appalling mess to consider her position.

"Theresa May must show leadership over the scandal – it is unbelievable that we have not seen a sacking or resignation in the Home Office."

The SNP's Westminster leader also turned his fire on the Prime Minster over the "misery and anxiety" experienced by those caught up in the controversy.

He said: "It was Theresa May who advocated the 'hostile environment' policies and championed the Tories anti-immigrant rhetoric. It was the Prime Minister who had to be embarrassed into meeting Caribbean leaders after initially refusing their requests.

"The deliberate decision to dispose of the landing cards of Windrush-generation residents was utterly unacceptable – whichever Westminster government decreed it.

May had claimed during PMQs that the landing cards were destroyed during under the previous Labour government in 2009.

"It isn't just incompetence, it is the intolerance and vindictiveness that has been displayed at the heart of this Tory government.

"The Home Secretary is the minister responsible – it was on her watch. Her position is untenable – and the clock is ticking for the Prime Minister."

A Home Office spokesperson said that people who had contributed to British society should not feel unwelcome.

"The Home Secretary has been clear, this is about people who have built their lives here in the UK and contributed so much to our society. We don't want them to feel unwelcome or to be in any doubt about their right to remain here and she has apologised unreservedly for any distress caused.

"The vast majority will already have documentation that proves their right to be here. For those that don't, we have established a new dedicated team to quickly help them get the documentation they need and ensure this is resolved as soon as possible.

"We've also set up a webpage and have been speaking to charities, community groups and High Commissioners to ensure advice and reassurance is provided to those affected."