A stark new economic analysis has projected that Britain could experience a dramatic population surge under the Green Party's proposed immigration framework, with numbers potentially swelling by 4.4 million individuals within just five years. The report, compiled by City investment bank Panmure Liberum, paints a contrasting picture of demographic outcomes depending on which political party assumes power after the next general election.
Divergent Population Projections Across Parties
The study estimates that if Green Party co-leader Zack Polanski secures victory in 2029, the UK population would skyrocket from 71.5 million to 75.9 million by 2034. This staggering increase is attributed directly to the party's advocacy for significantly relaxed border controls, which economists suggest could result in approximately 900,000 net arrivals annually.
In sharp contrast, the report forecasts a mere 200,000 population rise under a Reform UK government, equating to net migration of about 40,000 per year. The Conservative Party's policies are projected to yield an increase of 800,000 people, or 160,000 annually, while Labour's approach could result in growth between 1 million and 1.3 million over the next parliamentary term.
Policy Details Driving the Disparities
The Green Party's platform includes radical proposals to dismantle current immigration enforcement mechanisms. Internal policy documents reveal ambitions to abolish immigration detention entirely and grant amnesty to undocumented migrants, providing them access to public services including the National Health Service and social housing.
"Migration is not a criminal offence under any circumstances," state the documents, outlining a vision to "establish a system that recognises that all migrants are treated as citizens in waiting." Opponents have characterized these plans as "financially reckless but also dangerous," warning of unsustainable pressure on public infrastructure.
The variance in Labour's projection accounts for Home Secretary Shabana Mahmood's proposed extension of the permanent residence qualification period from five to ten years. Should this measure apply retroactively to current residents, the population would increase by one million; otherwise, growth could reach 1.3 million.
Expert Analysis and Party Responses
Simon French, Panmure Liberum's chief economist and former Civil Service economic adviser, emphasized the unprecedented policy divergence. "The spread of policies from the four leading UK parties could lead to a difference of more than four million in the UK population by the end of the next parliamentary cycle," he observed.
French noted that excluding immigration, Britain's population remains "basically stable," with natural changes showing a slight annual decline. "All the movement is net migration," he clarified, highlighting how the Green Party's projected 900,000 annual net migration dwarfs Reform UK's 40,000 and the Conservatives' 160,000.
The Green Party has dismissed the projections as "made up nonsense," asserting they've received no explanation of the calculation methodology. A party spokesperson defended their position, stating: "The Greens support a fair and managed migration system and successive governments have presided over a broken and unfair system. We are positive about the economic and societal benefits of immigration."
The spokesperson added that concerns about immigration stem from "a massive affordability crisis," and unlike other parties, the Greens "won't scapegoat migrants for the unfairness created by our rigged economic system."
Broader Context and Current Statistics
The Office for National Statistics projects a more moderate population increase of 1.6 million by the next parliament, based on current trends of natural change (with deaths slightly exceeding births) and net migration of 340,000 annually. The UK's current population stands at approximately 69.5 million.
These demographic forecasts emerge as the Green Party anticipates significant gains in upcoming local elections, with the party declaring that "in an ideal world, most border controls would not exist." The contrasting visions presented in the report underscore the profound implications immigration policy will have on Britain's future social and economic landscape.
