Patients with early stages of breast cancer in England are being forced to pay thousands of pounds for cancer treatment which their Welsh counterparts can receive for free.
The problem has come to light at the Royal Shrewsbury Hospital which treats people from Wales and Shropshire.
Those who live in England have to fork out £47,000 for the Herceptin drug, which is available free for the treatment of women with advanced stages of breast cancer but is not yet licensed for the disease's early stages.
North Shropshire MP Owen Paterson said he would be writing to the health secretary Patricia Hewitt about the postcode lottery.
"All these women in Shropshire have paid their taxes but they have had to raise huge sums of money while women two miles away in Wales are getting the drug in the same hospital for free," he said.
The Welsh Assembly Government decided in February that the drug should be free to all Welsh residents for the treatment of all stages of the disease.
In England, individual primary care trusts can decide how much funding, if any, to provide for treatment.
Click here to find out more information about our Shropshire care homes.