The UK risks absorbing the equivalent of a city the size of Edinburgh every year unless sweeping immigration reforms are introduced, Home Office officials have warned. They say the expected fall in net migration will stall, as official forecasts have consistently overestimated how many migrants actually leave the country—undermining assumptions that current levels will fall away over time.

Internal projections now suggest that net migration could settle at around 525,000 annually from 2028, far above the Government’s public assumption of 340,000. That figure is broadly equivalent to the population of Edinburgh, which currently stands at just over 530,000, officials noted. The stark forecast is based on the Office for National Statistics’ (ONS) “high variant” scenario, which was previously treated as a worst-case projection. Officials believe it now offers a more realistic picture of long-term migration trends, especially as outward migration has been significantly overstated in previous models.

A senior Whitehall source told The Times the working view within Government is that fewer migrants are returning home after work or study than expected, with many choosing to switch visas and settle permanently.

Home Secretary Yvette Cooper is expected to publish Labour’s long-awaited immigration white paper next week, outlining plans to reduce net migration and deliver on Sir Keir Starmer’s pledge to regain control of the system. It comes after net migration hit a record 728,000 in the year to June 2023.

New ONS figures due on May 22 are expected to show a drop in migration towards the end of last year. But insiders have warned the fall may only be temporary, driven by short-term visa fluctuations rather than structural change.

The White Paper is being positioned as a direct response to last week’s local election results, which saw a surge in support for Reform UK amid voter discontent over immigration. Key Labour advisers, including Morgan McSweeney, are pushing for firmer action. Ms Cooper is understood to back a tougher line and is expected to propose wide-ranging reforms.

These will include tightening the grounds on which failed asylum seekers and foreign offenders can resist removal on human rights grounds. In particular, the Home Office wants to limit the use of Article 8 of the European Convention on Human Rights, which protects the right to family life but is often invoked in deportation cases.

Ministers are also considering narrowing the legal definition of family ties to prevent estranged parents from making last-minute claims of involvement in their children’s lives in order to stay.

Since the end of free movement, net migration has been increasingly driven by arrivals from outside the EU. Many come through study routes, and a growing proportion remain in the UK after graduation. According to ONS data, half of those who arrived on student visas in 2021 had switched to another visa within three years, up from just 9% in 2019.

Officials say this pattern is not properly accounted for in current modelling and that it contributes to repeated overestimates of the number of people leaving the country each year.

At the same time, the economic models used by the Office for Budget Responsibility (OBR) are coming under renewed scrutiny. Senior figures argue they fail to reflect the long-term strain on housing, the NHS, and schools posed by rising migrant populations.

Although the OBR now estimates the average lifetime fiscal cost of each migrant at £20,000, these figures are not included in official economic forecasts unless the Treasury incorporates them in spending plans.

Professor Brian Bell, chair of the Migration Advisory Committee, said short-term thinking was undermining the policy response: “I think the problem is we’ve focused on the wrong thing.

“The thing we are focused on is ‘What is the fiscal impact in the next four years?’, because that is all the Government cares about when it comes to the fiscal rules and all the headroom that people talk about in the budget.”

A Home Office spokesman said: “Under the Tories, net migration spiralled out of control, hitting almost one million in their last year in office. At the same time, they hollowed out skills training, increasing the reliance on overseas workers, including a rise in employers bringing in low-skilled overseas workers.

“Labour’s immigration White Paper will clear up their mess, setting out new plans to reform the immigration system to reduce net migration and support economic growth.”