Earlier this month it emerged that 19 children and six pregnant women have been held at the centre since 2016, despite a commitment nearly a decade ago to end the practice.
In addition, nearly 3,000 people have been held at the detention centre in South Lanarkshire for more than 28 days. The UK is the only country in Europe to detain people in relation to immigration cases without any time limit.
The Home Office has defended its policies, saying that it is seeking to “avoid a situation where legitimate immigration control can be undermined by someone simply claiming to be a child”.
The department says the detention of children in immigration cases as routine practice ended in 2010.
At Westminster this week, Mr Javid told the SNP’s home affairs spokeswoman Joanna Cherry that the government’s kept its policy on at risk adults in immigration detention under constant review, but failed to offer any commitment on ending the holding of children and pregnant mothers.
Ms Cherry has now written to the Home Secretary calling for a time limit to immigration detention, and a definitive end to the practice of holding children at Dungavel.
Mr Javid, who is running for Conservative Party leadership and has the backing of Scottish Tory leader Ruth Davidson, has said he will introduce a fairer immigration system if he becomes Prime Minister, scrapping the 100,000 target for net migration.
After taking over the Home Office last year following the resignation of Amber Rudd over the treatment of the Windrush generation, he disowned the government’s so-called ‘hostile environment’ policy targeting illegal immigration.
But Ms Cherry described the continued detention of children “callous and inhumane” and claimed it was evidence of a continuing hostile environment towards immigrants, blamed for the Windrush scandal.
“Sajid Javid made the commitment to design a fairer immigration system – I ask him to stand by that promise as Home Secretary and re-think his government’s approach to immigration detention,” the SNP MP said.
“It is quite frankly hypocritical for Mr Javid to talk of a fairer immigration system whilst presiding over the only system in Europe that allows indefinite detention.
“It is also now incumbent on Ruth Davidson to say where she stands on this issue – and given her backing for Mr Javid as the next Prime Minister she should press him to do the right thing and urgently stop detaining children and vulnerable people, introducing a 28-day detention limit.”
Ms Cherry added: “If Sajid Javid will not do this, Scotland must have full control over these powers to take a new approach based on compassion and fairness – not punishment and isolation.”