Zimbabwe-born Brian White's story has gripped the country with more than 80,000 people now backing a petition for him to get a permanent visa.
Mr White, aged 21, who studied at Highfields School, Penn, was offered a place to study chemistry at Oxford after achieving 3 A*s and an A in A Levels last year.
But his application for a student grant triggered an investigation by the Home Office which found he had overstayed his temporary visa and faced deportation.
An application has now gone in for a permanent visa, but Mr White faces a race against time because a year's deferment made by the university's Lady Margaret Hall is set to run out.
Yesterday, Mr White travelled to Leicester to do a Life in the Uk test, as part of his application.
Today, Beverley Knight offered Mr White her support. She has pre-recorded a message for ITV's This Morning to be aired Thursday or Friday.
His plight has earned backing from award-winning columnist and writer Caitlin Moran and best-selling author Philip Pullman.
In a statement to the Express & Star, she said: "Simply put, Britain needs Brian.
"Why would the country reject someone who is regarded not only by himself but by his parents family and friends and indeed the wider public as a full British citizen.
"As a man who has been offered a place at Oxford he is exactly the kind of man we need for Britain's future."
Speaking this morning, Mr White, who moved to Penn with his adoptive family aged 15 from Botswana, said: "It's not the best.
"At the moment I have got an application with the Home Office which I hope will get resolved in the next few weeks.
"It's been seven or eight years [since I've been to Zimbabwe]. I haven't been to Zimbabwe since I was 12 or 13.
"I haven't got any connection there, so I don't know what I'd be doing.
"The Home Office haven't given me any sort of notice about what way it's going to go, so I still don't know."
Baron Philip Charles Harris, of Peckham, joined the thousands of supporters behind Mr White.
Speaking on BBC Radio 4, he said Mr White should remain in the country and he would write a letter voicing his support.
He said: "I think he should definitely be allowed to stay in this country, he's been here for seven years.
"He's done fantastically well, to get to Oxford in maths, he's got to be very good, and it's one subject I was quite good at.
"If I can help in anyway, if I can write in on my House of Lords paper, I will because he should be allowed to stay and have a great education at Oxford."
Last night, an online petition started by friend Luke Wilcox, 19, for Mr White to remain in the UK and study at Oxford had more than 82,000 signatures.
A Home Office spokesman said: "We understand the urgency of Mr White's case and are looking to resolve his application as soon as possible. Brian entered the UK in 2012 as the dependant of his parents.
"In 2014, he applied for naturalisation as a British citizen, which was refused as he did not qualify under the immigration rules. In April 2017 he submitted a further application for leave [to remain] under a different category. This remains under consideration."