Stanley Johnson is an environmentalist and author who is a former Conservative MEP and parliamentary candidate.

In recent weeks, the debate over immigration has been taken over – I hesitate to use the word ‘swamped’ – by humanitarian issues. The sight of drowned children on Mediterranean beaches, hordes of refugees at railway stations in Hungary, or migrants congregating at Calais in a desperate bid to reach Britain – these have all understandably grabbed the headlines.

When the hubbub has died down, and some temporary fixes have (hopefully) been found to end the current crisis, I hope the Prime Minister – and in particular the Number 10 Policy Unit, where Camilla Cavendish is in charge (having succeeded my son, Jo, the MP for Orpington, who is now Minister for the Universities and Science) – will revisit a fundamental issue that has been on the back burner for far too long: namely, the issue of ‘population’.

There are at least two important questions. Should Britain itself have a population policy? And are we doing enough to help developing countries curb their own population growth?

As far as the first question is concerned, there are some useful files to be discovered in the archive. In 1949, the Report of the Royal Commission on Population was published. It recommended, inter alia, that the Lord President of the Council, who at the time had responsibility for population matters, should be responsible for a continuous watch over population movements and their bearing on national policies. This last recommendation was, in my view, particularly important. Unfortunately, it was not implemented.

More than 20 years later, the House of Commons Select Committee on Science and Technology, noted in 1971 that the Lord President of the Council had not assumed the duties proposed by the Royal Commission, nor had any specific allocation of such duties been made to Ministers. The Select Committee went on to conclude that ‘the Government must act to prevent the consequences of population growth becoming intolerable for the everyday conditions of life.’

The Select Committee saw fit to quote, with evident approbation, a Conservation Society statement as follows: ‘The Conservation Society believes that the quality of life is crucially dependent on the amount of land and the pressures upon it, that on this criterion Britain is already overcrowded and additional numbers can only diminish the quality of life.”

In spite of the fact that the Campaign Guide 1970, published for the General Election of that year, stated the Conservative belief that the ‘question of continued population growth in Britain is central to all other issues’, the Party during the course of the election campaign placed little stress on the need to deal with Britain’s own demographic issues.

Nor, as far as I am aware, has the ‘population issue’ featured since then as a major item on the political agenda. In the days when I worked on environmental questions in the Conservative Research Department (from 1969-70), I once asked Reggie Maulding, then the Party’s policy supremo (the Oliver Letwin role today), why the Conservatives didn’t say more about population. Maudling put his arm around my shoulder, and said: “Not one for the hustings, dear boy!”

I thought Reggie was wrong then, and I still think so today. Almost 45 years after that Select Committee published its report, the time has surely come for political parties of all persuasions to revisit the population issue. This is not something that can be ducked any longer, on the ground that is ‘too controversial’ or whatever.

The findings of the UK’s Office of National Statistics suggest that natural growth in the UK is currently at its highest level since the so called ‘baby boom’ years of the 1960s. This natural change, the difference between the current birth rate and death rate, is also reported to be responsible for over 52 per cent of our population’s growth.

The current estimate for the UK’s population in 2014 is 63.7 million, making the UK the world’s 22nd largest country by population. A total population of 78 million projected is projected for 2037, implying an extra 5.2 million households by that date – an increase of 4000 households per week.

5.2 million more households by 2037! What does that mean in terms of demand for food and housing, health and welfare, transport, energy, and education? What are the implications in terms of pollution, waste and the general impact on the environment? What does it imply for our already strained efforts to protect landscape and the countryside, and the wild places which mean so much to us?

What tools are available, for example in terms of social incentives or disincentives, to reduce this country’s population growth and to bring it back to more manageable levels? All these questions need to be urgently explored.

The issue of migration is of course of fundamental importance in the overall demographic picture. UK’s key population statistics are increasingly influenced by migration. During Labour;s 13 years, net inward migration totalled a staggering 3.6 million. There has also there been a significant introduction of women born overseas who are of child-bearing age, and inclined in any case to favour large families.

The Prime Minister is already desperately seeking ways to redeem his ‘no ifs and buts’ pledge to reduce the rate of net immigration (currently running at 300,000 a year). If that involves a rupture with the EU over the ‘freedom of movement issue’, then – in my view – it is a price which must be paid as we seek to bring the UK’s currently totally out of control rate of population growth back into some kind of reasonable framework. And I say this as someone who has long been pro-Europe. For me, the issue is totally fundamental. This is a personal red line.

As far as immigration from third countries is concerned, here too – I would argue – we have to take back the control of our borders which we appear to have lost, de facto if not de iure. In doing so, we will need to look carefully at the burdens laid on us under treaties which were signed and ratified before the era of mass migration began. The place to solve the migrant and refugee crisis is in the countries where the potential migrants and refugees originate.

One important element in this complex problem is to ensure that our overseas aid programmes (the 0.7 per cent of GNP now legally ring-fenced), deliver effective assistance to population and family planning programmes in the recipient countries, as well as maternal and child health care and female education, both of which are essential not only in their own right but as the vital underpinning of birth control efforts.

The harsh truth is that, in vast areas of the globe, birth-rates remain much too high and per capita incomes ridiculously low. The ‘push’ factor (escaping poverty, disease, unemployment) may be as important as the ‘pull’ factor (seizing better opportunities abroad). Distinctions between refugees and migrants are in such circumstances largely theoretical. You’d need to be blind to fail to see the connection between high rates of population growth, mass poverty, environmental degradation, and political instability.

Tackling the population problem – whether at home or abroad – is not easy. Some politicians, such as Mrs Gandhi, who courageously sought to bring family planning to the over-300,000 villages of India, ended up unexpectedly on the funeral pyre. But at least she tried.

The second volume of Stanley Johnson’s memoir ‘Stanley I Resume’ is published by the Robson Press. He is also, inter alia, the author of World Population and the United Nations, Cambridge University Press 1987. World Population – Turning the Tide, Kluwer Academic Publishers 1994 and The Politics of Population, Earthscan 2009.