A Tadworth mum is fighting for a “lifesaving” cystic fibrosis drug to be available on the NHS after her daughter suffered irreversible lung damage.

Mum-of-three Sharon Cranfield, whose 16-year-old daughter Jessica has cystic fibrosis, said she doesn’t know long she will live, something she’s been aware of since she was just nine-years-old.

Diagnosed as a baby at three months, Jessica sometimes had to spend months at a time in hospital because she was so sick.

Sharon said: “One time when Jessica was in hospital she made friends with a little girl her own age; they waved at each other through the window.”

The girl also had cystic fibrosis, and sadly passed away.

“My daughter went to her funeral when she was only ten years old. Imagine being ten years old and seeing that tiny casket with pink flowers all over?

“What could I have done? She wanted to say goodbye to her friend, and her mother put her letter on top of the coffin.”

Jessica was never able to have any physical contact with her friend because of the risk of passing each other infections that only harm people with Cystic Fibrosis.

Now at 16, Jessica is one of the few to be given Orkambi, a new precision medicine for cystic fibrosis, on compassionate grounds by the pharmaceutical company Vertex which created it.

Sharon describes the drug as “lifesaving” and said Jessica has improved since taking it.

However, Jessica was only given it because she was so ill - the lung damage she’s endured is irreversible.

“Imagine trying to breathe through a straw,” said Sharon. “You will always feel like you’re suffocating. That is what it’s like.”

Sharon hopes that if enough people sign the petition, other children will be able to receive Orkambi before they get permanent damage.

Currently, children with cystic fibrosis take a cocktail of medicines such as steroids, antibiotics, and digestive enzymes, drugs that widen the airways, and drugs that thin the mucus.

They will usually have to have physiotherapy to help clear the lungs and use nebulisers to help with breathing.

Currently, fewer than 50 per cent of people with cystic fibrosis will live to reach their 40s.

The petition has more than 50,000 signatures since being launched on Wednesday night (January 17).

When it reaches 100,000 it will be considered for debate in Parliament.

Sign the petition here.