The history of humanity is the history of human migration. To ask whether migration is a good or bad thing is as absurd as asking whether we should have stayed as hunter-gatherers, living in nomadic tribes, or whether the development of agriculture was a positive move. Migration is a fact of life.

Every continent and country is shaped by the movement of people across its contours: people in search of resources, land, religious freedom, political asylum and the opportunity for a better life. Europe is no different. For centuries people have moved into Europe, out of Europe, and within Europe, shaping our trade, culture and cityscapes.

In the United Kingdom, our experience has been overwhelmingly positive. Migrants have boosted our economy, enhanced our culture, and made our country immeasurably better. The experience of EU migration has also been positive, providing workers for everything from social care and the National Health Service to food processing and the financial institutions of the City of London.

There is a broad perception that the UK’s borders are open, and need to be controlled. This was the ‘Leave’ campaign’s trump card in the referendum campaign. So, alongside the broad philosophical argument in favour of migration, we need to make a practical argument for safe, secure borders, and a sense that migration is a managed process.

Of course, we have border controls now, within the EU. That is why we queue on return from trips abroad. Our borders are controlled. Every year about 5,000 EU citizens are denied entry to the UK on security grounds. But this is clearly not sufficient to give people faith in the system.

As we leave the EU, we will shape our immigration system, not just for the period of ‘transition’ but for the decades ahead. This will have profound effects on our economy and our prosperity. If we get it wrong, we will suffer a brain drain in the industries, such as the digital sector, we need to grow, and a labour shortage in the agricultural, building and service sectors we all rely on.

At Progress, we are campaigning to stay in the single market, so that Brexit does not mean significant damage to our economy. But we also need to campaign for a form of free movement which both fuels our economy with fresh energy and talent, and at the same time reassures people. That might mean Belgium-style measures on stay without a job or a German-style worker registration scheme. It might also mean ID cards for all UK citizens (and not just ‘foreign workers’) to enhance our sense of citizenship. The latest Progress magazine has a 10-point plan tackle this holistically.

We have an opportunity here. We can introduce measures which reassure those who are fearful about a borderless UK and a migration free-for-all, and allow a more sensible and measured debate about the benefits to the UK of migration. At the same time we can avoid the economic trauma of hard Brexit and the swift discovery that there are not enough people to, for instance, care for our elderly.

Brexit will change Britain’s immigration rules. There is no avoiding that, so let us work out what it is we want.

The cost of crashing out the single market – the result of ending free movement – is estimated at around £45billion a year. That, then, is best avoided.

Instead, we can fashion a new relationship with our economic partners, within the single market, where we retain our rights as consumers and citizens alongside the ability to attract the brightest and the best from across Europe and the world. The alternatives look set to be much more regressive.