Yes, the UK population is set to rise – but without immigration, we’d be a lonely, isolated isle

The Office for National Statistics projects that immigration will increase the UK population by 5 million in a decade – but the alternative is for Britain to be poor and cut off, writes John Rentoul

A paradox of public opinion is that immigration is unpopular, but immigrants are not. Most British people say that immigration numbers should be lower, but when they are asked about the jobs that immigrants do, they are in favour of more people coming to live in the UK or the numbers staying the same.

That applies most of all to doctors, nurses, care home workers and engineers, but there is no majority for reducing the numbers of even the most unpopular occupation – bankers – according to a recent survey by Ipsos.

So although today’s projection by the Office for National Statistics (ONS) that the population will increase by 5 million in a decade may seem alarming, there are some things that should be remembered.

Above all, the bottom line is that economic success and net immigration go together. This is not the same as saying we need doctors and care workers or else the NHS and social care system will break down. Opponents of immigration are entitled to respond to that by saying that we should train the workers we need in Britain.

But it is not as simple as that. The only sure way to put an end to net immigration altogether – which is the objective set by Nigel Farage, the Reform leader – is to make the country such an economic basket case that more people want to leave than to move here.

As Tony Blair once said, “It is a good rule of thumb to ask of a country: are people trying to get into it or out of it?”

If Farage succeeded in making Britain sufficiently unattractive to reduce net immigration to zero, we could train as many doctors as we liked, but they would emigrate – even more than they are doing now – to Australia, Canada and elsewhere.

The link between moderate levels of net immigration and economic prosperity is not just the direct contribution made by new workers, or the fees paid by international students, but the association between prosperity and an open economy.

This argument is complicated by the sudden increase in immigration since Britain became responsible for its own borders policy, after the end of the Brexit transition period in January 2021. All but the most liberal would agree that immigration running at 906,000 a year, as it was on revised figures in the year to June 2023, was unsustainable.

It was an extraordinary mistake for a government elected to “get Brexit done” to make. Regardless of Boris Johnson’s own liberal instincts on immigration, he knew that millions of people voted to leave the EU because they wanted to reduce immigration. He must have known that, if net immigration tripled instead, this would be a disaster not just for him and his party but for trust in democratic politics as a whole.

The kindest interpretation, therefore, is that he had no idea what he was doing, and was unaware that his much-vaunted “Australian-style points system” was allowing far more immigration from outside the EU than free-movement rules ever allowed from the EU itself.

Now that the numbers are heading back to the pre-Johnson normal, though, we can have a reasonable debate about the optimum level of immigration – although that would be helped if the government could get to grips with the most visible form of unfair and unpopular immigration, namely the small boats.

Public opinion will accept a moderate level of immigration if it is seen to be fair, because people understand that a prosperous economy has to be open to the world.

The point is reinforced graphically by the ONS’s projection of what would happen if Britain managed to operate Farage’s “net zero” immigration policy. It suggests that the population would start to decline significantly after 20 years, and that it would halve after 100 years, going down from 67 million to 35 million.

The most numerous age would be 75 and it would be a society of few children. What the ONS does not say is that this could happen only if Britain became a closed, impoverished country and remained so for decades.