Immigration will account for three-quarters of population growth over the next 25 years as the number of people living in Britain rises to almost 73 million.

The UK’s population will increase by 7.3m people between 2016 and 2041, a rise equivalent to 11.1 per cent, seven cities the population size of Birmingham. The Office for National statistics (ONS) said that the rise will be driven by direct migration and increasing numbers of migrants having children once settled in the UK. Because migrants are concentrated at young adult ages, the impact of migration on the projected number of women of childbearing age is especially important over this period.

Migration Watch, the immigration watchdog group, suggested that the figures may significantly underestimate the number of migrants coming to the UK.

Lord Green of Deddington, the organisation’s chairman, said: “Given that net migration has averaged about 250,000 a year over the last ten years, the immigration assumption of 165,000 underlying the principal projection is extraordinarily low. This is serious because it will lead to inadequate planning for housing, schools, hospitals and infrastructure – as, indeed, we have seen in recent years. Yet again the ONS have been much too cautious.”

Britain’s population will grow significantly more than EU nations. According to separate statistics produced by Eurostat the UK’s population is forecast to increase by 16 per cent between 2015 and 2040. This would result in a total population of 75 million by 2040, significantly higher than the estimate given by the ONS. Without migration Eurostat estimates the population by 2040 would only be 66.7 million. By contrast France’s population will grow by 10 per cent, Germany’s by 4 per cent and Italy’s will see a slight decline.

UKIP’s Immigration spokesman John Bickley said: “The ONS projections of significant population growth over the next 25 years, seven cities with populations the  size of Birmingham should be a wake up call for the complacent and reckless Labour and Tory parties, who between them have flooded the UK with uncontrolled immigration since the early ’90’s. Worryingly, Migration Watch believes the ONS have grossly underestimated the growth.

When will the British people realise that the established parties have no intention of controlling immigration as they are in hock to ‘big business’ and the corporatist EU which wants to turn the UK in a low wage sweatshop off the coast of Europe

Our public services and housing are already under enormous pressure. Can the government explain how adding another seven ‘Birminghams’, mainly comprised of migrants to our population is sustainable, in the interests of social cohesion and working class wages and living standards?”