A week later, she underwent a seven-hour operation to remove lymph nodes and a section of her tongue.
This week Jay declared that the surgery had been successful but does not know if she will ever sing again.
“My surgeon came in 10 days after my operation to tell me himself. I was elated – there were tears of joy. I’m here to tell the tale, to be a mum and a wife,” said the singer, who has a 15-year-old daughter Josie with husband Dave Colquhoun.
Jay discovered she had precancerous cells in April following years of screening due to a rash on her tongue called lichen planus, an autoimmune condition.
Only two per cent of cases mutate to cancer but hers did. A section of the left side of her tongue was removed.
Surgeons reconstructed it with part of her upper thigh, including a major nerve, which they inserted through a long incision along her jawline.
Lymph nodes were removed from her neck and a tracheal tube inserted in her throat, which has now been removed. She was discharged 10 days after surgery and survived on soup.
Only in the past week has she been able to eat solid food.
The inside of her mouth and throat is still swollen and she speaks with a lisp and slurs her words.
At the time of her diagnosis Jay had been singing with two of the original Bucks Fizz line-up – Cheryl Baker, 64, and Mike Nolan, 63, as new band The Fizz.
“I’m very, very lucky they caught it,” she said. “But I know I will never really look the same, dance the same, or sound the same.
“There is a chance I will always have a lisp.” Two weeks ago, Jay practiced her scales even though opening her mouth was painful.
She said: “It was nerveracking to attempt singing for the first time.
“I have noticed my voice is different. “I suppose because my tongue is different.
“I don’t suppose I’ll ever be as I was but hopefully I will be able to sing. It’s an unknown.