A group of hundreds of professors, health experts, doctors, and politicians across UK political parties have signed on to letters calling for medical marijuana to be available for free in the United Kingdom. To make medical cannabis available at no cost to patients, prescriptions have to come from the National Health Service (NHS), the UK’s comprehensive, universal, and free-at-the-point-of-service medical system.

Prescribing medical cannabis on the NHS is currently legal in the UK under certain circumstances. But a number of restrictions and bureaucratic obstacles have so far deterred any NHS specialists from prescribing medical cannabis treatments. In their letter, drug and health experts, along with members of Parliament, urge UK Health Secretary Matt Hancock to ease those restrictions. And in another letter, another group of MPs representing Liberal Democrats and Labour have asked Prime Minister Boris Johnson to intervene on behalf of patients unable to obtain medical cannabis prescriptions.

After nearly a year under the UK’s highly restrictive rules for accessing legal medical cannabis, doctors and politicians say its time for a change. They say the current system of controls isn’t working to put medical cannabis in the hands of patients who need it most. And as a result, patients are dying unnecessarily, experts say, from addictions to dangerous painkillers and from symptoms that could be treated effectively and more safely with cannabis.

“The failure of the medical and pharmacy professions to embrace [medical cannabis] being made ‘legal’ is a great worry to patients and carers, and will already have led to more preventable deaths from conditions such as epilepsy,” argue senior doctors and MPs in their letter to Health Secretary Hancock.

According to a recent study from Public Health England, a quarter of all adults in the UK use strong painkillers, sleeping aids, and anti-depressants. Many doctors and researchers, along with patients themselves, have said that cannabis can treat underlying conditions better than those medicines.

Experts in the UK want Hancock to remove restrictions and make it easier for NHS doctors to prescribe medical cannabis. Specifically, they want to do away with rules requiring senior medical doctors to sign off on specialists’ prescriptions. They also want the regulations for importing medical cannabis products simplified. And in perhaps the most important ask, they want general practitioners, not just specialists, to be able to write cannabis prescriptions.

The proposed changes to the rules governing medical cannabis could make an immediate change in the lives of many patients. With a prescription from a medical provider on the NHS, patients would be able to obtain cannabis at no charge. Without one, patients who can afford to are turning to private caregivers, where medical cannabis prescriptions can run upwards of $1,250 each month. The high cost ends up driving many patients to unregulated cannabis products for relief.

But health experts, professors and MPs also want to see a longer-term effort to support medical cannabis access. They say educating doctors about medical cannabis and training them how to prescribe it is necessary to overcome physicians’ fears they’ll make a mistake. Health experts wants to see medical cannabis treatments available for patients suffering from a range of conditions, including epilepsy, chronic pain, anxiety, multiple sclerosis, insomnia, depression and others.

But the National Institute for Health and Care Excellence (NICE), a corporate think tank that advises on national health and social policy, responded to the letters by citing a “lack of clinical evidence to support the use of cannabis products.” NICE does support ongoing efforts to study medical cannabis. In November, Imperial College London Professor David Nutt, a leading drug expert, will launch an independent clinical trial involving 20,000 patients.