It would not be appropriate to "interfere" with the case of a teenager facing deportation to her native Mauritius, Home Secretary Theresa May said.
She said the plight of teenager Yashika Bageerathi had gone through the "proper process" and she would not be stepping in to prevent her deportation.
The 19-year-old came to the UK with her mother, sister and brother in 2011 to escape a relative who was physically abusive and claimed asylum in the summer of 2013, although a ll four now face deportation.
It seemed she had been given a last minute reprieve on Tuesday, when British Airways appeared to refuse to allow her to board a flight from Gatwick Airport.
The campaign was dealt a blow on Tuesday evening when her mother, brother and sister were told they also faced the threat of deportation after receiving a letter from the Home Office telling the mother she had no grounds for appeal.
Ms May told Sky News: "Yashika's two claims to appeal against the decision on her asylum claims have been dealt with by the judges, they've been looked at by the judges and I don't think it's appropriate for a politician to interfere in that legal process.
"It's gone through proper process, the judges have looked at the various aspects of her asylum claims and they have taken clear decisions."
But a spokesman for Oasis Hadley Academy in Enfield, north London, where Ms Bageerathi studies, said they believed Ms May was not making a judgment about the student's claim but only stating that she could not get involved in the case.
The spokesman added lawyers were still working to get Ms Bageerathi released from Yarl's Wood Immigration Removal Centre in Bedfordshire, where she has been since March 19.
In a brief conversation, the sixth-former said she was still in Yarl's Wood and she did not know whether she would be released today. She added she was "not feeling well".
David Burrowes, Conservative MP for Enfield Southgate, said he made "further representations to the minister requesting Yashika's release on bail" today but had not heard anything back from the Home Office.
Ms Bageerathi's fellow pupils have used social media and demonstrations to protest against the decision to send Ms Bageerathi back and continue their campaigning online.
A petition by the students calling on Immigration Minister James Brokenshire and Theresa May to stop the deportation and allow the student to complete her A-levels garnered nearly 140,000 signatures on change.org.
The Home Office has refused to comment on the case.