If our politicians don’t act fast British businesses are going to be left behind in the race to commercialise cannabis across the world. By 2025 the global market for medicinal cannabis alone is due to be worth £40bn, and by 2021 the recreational market in the US alone is expected to be worth $24.5bn. The prohibition on research, development, innovation and sales of cannabis is holding British business back at a time when we need to be even more innovative and even more global in our trade ambitions.

In our 2016 report The Tide Effect report we estimated that the legal UK cannabis market could be worth £6.8bn annually, produce benefits to the government of between £750m and £1.05bn in tax revenues, and lower criminal justice costs. The numbers of offenders in prison for cannabis related offences in England and Wales would also be likely to drop from the current 1,363 inmates which currently costs the taxpayer around £50m a year.

Since we released The Tide Effect, more countries have moved towards legalisation and understanding the greater market potential the industry could bring. Last week California joined the ranks of American states to legalise recreational cannabis sales, which will drive billions of dollars of investment and create thousands of jobs, in a nascent industry. Canadian cannabis product manufacturer Aurora is expanding into Europe, sensing an opportunity to dominate a new market.

With more foreign direct investment flowing into the UK than any other country in Europe we would be well placed to get a new industry, with new export potential and a global reach, off the ground.

They’d have a pretty healthy market at home too of course. 6.5% of Britons have used cannabis in the past year. That’s 2.1 million people. But at the moment, they’re all criminals in the eyes of the law and forced to buy it from criminal gangs. Beyond the business case, that many people being criminalised by prohibition is making an ass of the law.

The image of stoners that campaigners against liberalisation use is outdated too. Nearly a million people use medical marijuana in the UK at the moment, so many in fact that the Council of the Royal College of General Practitioners (RCGP) has said it will issue guidelines for doctors on how to advise patients that are self-medicating currently.

But while we might be convinced of the benefits of being liberal we might have some work to do with the Conservative Party here in the UK. Their cousins in the Liberal–National Coalition in Australia have learned though and they’re making the case from a thoroughly Tory position. Australian health minister Greg Hunt last week announced that his party’s “goal is very clear: to give Australian farmers and manufacturers the best shot at being the world's number one exporter of medicinal cannabis.” Now, it would be great to see them embracing the choice of the consumer on recreational cannabis use too, but it’s a start.

We don’t need to be criminalising a whole section of society, we don’t need to be holding back British entrepreneurs, innovators and agriculture, and we don’t need to be driving consumers to the black market and potentially dangerous products. None of these things are conservative values and our Conservative Party should wake up to the dangers their stance on this issue is causing.

Enterprise, innovation, freedom of choice and personal responsibility are key to the debate on cannabis. Tories shouldn’t support marijuana legalisation despite being conservative. They should support legalisation because they are conservatives.