Thousands of women with breast cancer are missing out on 43p-a-day drugs which could stop their disease spreading, new research suggests.

A poll of cancer specialists found there was confusion over who funds bisphosphates - cheap drugs typically used to treat osteoporosis but which are also given to women with postmenopausal breast cancer.

The drugs alter bone tissue, making it harder for cancer cells to survive there, and are already used for patients with advanced prostate cancer.

They have been hailed as having the potential to prevent around 1,000 or one in 10 breast cancer deaths, and could save the NHS millions of pounds every year.

Breast Cancer Now calculates that around 27,000 women every year are missing out on bisphosphonates, with the main reason cited being a lack of clear guidance on who should fund them.

Baroness Delyth Morgan, chief executive at Breast Cancer Now, called for a national policy on who would fund the drugs, such as centrally through NHS England or via local clinical commissioning groups (CCGs).

Postmenopausal women on bisphosphonates saw a 28% reduction in the chances of their cancer coming back.

The drugs also cut the risk of dying from the disease during the first 10 years after diagnosis by 18%.

Analysis by Breast Cancer Now shows the cost of giving women the drugs would be almost £17 million a year, but would save money in the long-run as it would leave women needing fewer bone scans, while around 1,200 fewer women every year would develop secondary breast cancer.

Rob Coleman, professor of medical oncology at the University of Sheffield, said: "It should be an absolute priority for every clinician and commissioner involved in the provision of breast cancer services to ensure this simple and safe treatment is made available, as a matter of urgency."

NHS England said decisions on the funding of the drugs were currently made locally.