Lord Hodgson is a Conservative peer.

It is quite understandable, and indeed an attractive reflection of our nationally tolerant attitudes towards new arrivals, that the UK public takes a relaxed view of an increased number of arrivals from Hong Kong – a combination of an understanding of our moral debt and the reputation of the Chinese as industrious and hard working underpins this.

But this short term decision has not been factored in to considerations of the longer-term demographic implications. No-one doubts the positive impact of some immigration, the worry is about scale. When the Blair Government opened the doors to large scale immigration in the late 1990’s the population of the UK was 58.1 million, it is now 66.4 million, an increase of over 8 million.

The Office for National Statistics latest projection for 25 years from now is another increase of five million – before allowing for any substantial number of arrivals from Hong Kong. So in half a century, the population of the UK will have increased by over 20 per cent.

The Government’s short-term arguments focus on the economic advantages – usually measured by growth in GDP. But growth in total GDP is a poor measurement: median GDP per head gives a clearer measurement of economic performance across the whole population. The fact that it has increased little in the last ten years shows that the major beneficiaries of recent demographic change have been the better off amongst the existing population and the new arrivals themselves – and good luck to them.

However, for the young person on a zero hours contract, for a member of a minority community in a low pay, low prospect job or for an over 50 struggling to find a job at all the picture is not so rosy. And this is before the externalities. Of course, the short term focus is on the potential increase in pressure on hospitals, schools and public services generally.

But there are more serious underlying long term trends. For example, we shall run short of water – particularly in the South East – over the next 20 years. And we have to think how we shall be able to feed ourselves in an increasingly uncertain world. Public concern about damage to our environment and our ecology is rising.

There is no way we can expect to house five million more people without the inevitable result increase in urban sprawl – further damaging both. The figures suggest we will have to build over an area the size of Bedfordshire by the 2040’s. New building arouses intense opposition wherever it is planned, and nowhere more than in Tory held shire seats.

The United Kingdom is rich in many, many ways but it is poor in one critical way: we are short of space as a result of us being a small, already relatively crowded, island.

There is an urgent need to establish a cross-departmental body within government to analyse and weigh up these many factors in a transparent evidence-based way. I have long suggested that an office for Demographic Change – on the lines of the Office for Budget Responsibility – would be a good first step.

No-one can fail to feel sympathy for the people of Hong Kong, or indeed for the millions of refugees around the world. But our wish to help needs to be balanced by a consideration of the country we shall be leaving to future generations: demography is indeed destiny.