By Jane Elliott BBC News health reporter

Emily needs oxygen and regular medication

There are too few organs available for transplantation and, although 90% of the population has said they support organ donation, less than a quarter of these are on the register.

There are currently over 6,500 people waiting for organ transplants, but less than 3,000 are carried out each year.

Last year alone over 400 people died while on the waiting list.

Campaign

Emily, aged 22, and Emma Harris, 32, who both have cystic fibrosis, have launched a campaign to raise awareness of the national organ transplant shortages and to encourage people to register.

They are also selling T-shirts with the logos 'I'd give you one...' and 'Live life then give life', to encourage people to show their support for organ donation.

I have so much I want to do, get a job, go abroad again, and get my own house Emily Thackray

Emily, who lives in Surrey, is aware that time might be running out for her.

She and Emma have already lost 15 friends between them to CF, but she is determined to fight for herself and others.

"I know my life is on the line and the reason I am working so hard at this is that it is a matter of life and death.

"I am fiercely determined to be in that 50% that gets a transplant, and optimistic that somewhere someone will make that amazing decision to give the gift of life, and donate their organs after their death.

"I have so much I want to do, get a job, go abroad again, and get my own house. But I have lost many friends over the years whose time just ran out, so know that the threat is only too real.

"Whilst I am not scared of dying, I love my life with a passion, so the thought of not being here makes me incredibly sad.

"Even if this campaign doesn't save my life, hopefully it will save others, and I am determined to fight till the end."

Register

Emily, who is now on oxygen 24 hours a day, said that she wanted to raise awareness as many people had not even considered donation.

"I understand that whether people donate or not is a matter of personal choice and I have no problem with that.

"What I want to do is target the people who want to donate and haven't got round to it or those who have never thought about it.

"My message to people is please think about registering and please do tell your next of kin."

The t-shirts designed to raise awareness

In the meantime Emily must just wait and hope for the call from Harefield Hospital to tell her that they have compatible lungs waiting for transplant.

"After I first joined the register I used to jump every time the telephone went, but 15 months later I am still waiting."

A spokesperson for the Cystic Fibrosis trust urged everyone to join the register to give hope to people waiting for transplants.

"Emily Thackray is living life on the list with tremendous courage and optimism and is a real inspiration to the CF community."

UK Transplant manager and transplant director Chris Rudge agreed: "Transplants save and enhance thousands of lives every year, but there is a desperate shortage of donated organs.

"About 400 people die every year while waiting. Deaths could be avoided if more people agreed to donation and made their wishes known.

"Putting your name on the NHS organ donor register is the best way to make your wishes clear, but it is also vital to let your family know what you want.