Labour has promised to scrap prescription charges in England if it wins power.
The move would bring England into line with Scotland, Wales and Northern Ireland, where they are free.
Currently, prescriptions cost £9 per item in England, unless patients opt into the NHS pre-payment discount scheme.
Labour leader Jeremy Corbyn said the policy, which the party estimates would cost £745m annually, was a “common sense” move.
“Healthcare is a human right. People should not be forced to worry about the cost of their medicines,” he said.
“Bringing England in line with the rest of the UK by scrapping prescription charges for everyone is simple common sense and part of our plans to expand and upgrade our public services for the many, not the few.”
Shadow health secretary Jonathan Ashworth, who will announce the pledge in his speech to Labour’s annual conference in Brighton on Sunday, said the cost “puts people off taking the medicine they need”.
He said: “Not only do people suffer illnesses and the effects of illnesses more than they need to but, in the long term, it costs the NHS more money because those people who don’t take their medicines present with even more serious conditions later on.
“The NHS could actually save £20m a year if they lifted prescription charges for people with just two conditions: Parkinson’s disease and inflammatory bowel disease.”
A survey of health professionals by the Royal College of Nursing found that 87% had patients skip medication because of the cost of their prescription.
Research by Asthma UK found that more than three quarters of people with the condition struggle to afford their prescriptions, while a survey found that one in three people with rheumatoid arthritis have not collected a prescription due to the cost.
The British Medical Association’s Dr Farah Jameel welcomed the announcement.
“The BMA has repeatedly called for prescription costs to be abolished,” she said.
“Prescription charges can be a huge expense, particularly for patients living with long-term conditions.
“Getting rid of them will mean more people are able to take the medication they need without having to worry about how they make ends meet; how they choose between paying a bill and buying food or paying for their prescription.”
But health minister Nadine Dorries said it was “yet another promise that Labour cannot deliver”.
“Almost 90 per cent of prescriptions are already dispensed for free so this would be a handout for the few who can readily afford to pay,” she said.
In his speech, Mr Ashworth will also promise to increase the number of GP trainees in England by nearly 50%.
In addition, Labour’s health spokesman will outline the party’s plans to make the NHS the “greenest health service in the world” and ensure it meets a net zero carbon emissions target.