A Cornish cancer patient is threatening to sue the NHS for breach of her human rights in a row over a potentially life-extending drug.
Debbie Hirst says the drug Avastin could extend her life
Debbie Hirst, 56, from Carbis Bay, wants to pay privately for the breast cancer drug Avastin.
But she has been told that if she starts taking it privately her free treatment on the NHS, including scans and blood tests, will end.
The government says it could lead to a two-tier system.
The Royal Cornwall NHS Trust said it had received Department of Health guidelines underlining official policy that allowing patients to contribute towards NHS care - known as co-payment - was against the principles and values of the NHS.
A lawyer has offered to help Mrs Hirst take a civil action against the NHS saying that her human rights are being ignored.
Mother-of-two Mrs Hirst said: "It is my human right to a life.
"This drug could extend my life and if I have to go down this route I am prepared to do it.
"I have nothing to lose."
The Department of Health said in a statement: "It is a fundamental principle of the NHS, supported by all the main political parties, that treatment should be free at the point of need.
"Co-payments would undermine this."