Health minister Melanie Johnson has promised to end an NHS postcode lottery for breast cancer victims.

The pledge came as the charity CancerBACUP said that just one third of the women who could benefit from the drug Herceptin are receiving it.

Studies have shown that Herceptin can help women diagnosed with the worst forms of breast cancer.

And the government's drug watchdog, the National Institute for Clinical Excellence, has said that the NHS should pay for the drug, a decision estimated to cost the taxpayer £17 million per year.

But a survey carried out by Herceptin manufacturers Roche found that only a third of suitable patients were getting it, depending on where the cancer victims live.

In the Midlands only 14 per cent of eligible women get the drug, compared with 61 per cent of patients in South East England.

CancerBACUP demanded the government end the latest "postcode lottery".

Chief executive Joanne Rule said it was "daft" that the Department of Health could not monitor the regional take-up of the drug.

"It's daft that the only way that the NHS knows what's being prescribed is if the manufacturers tell them," she said.

Speaking on Thursday Johnson committed to ending the postcode lottery and said the cost of the drug would not be a barrier.

"We are committed to ending the postcode lottery so that patients who need vital drugs are not denied them on the grounds of funding," she said.

"I have asked strategic health authorities to look closely at this new evidence and raise it at a local level with the trusts that provide services.

"Patients should be getting the drugs they need and we will do all we can to resolve the problem."