Accuracy Assessment: Largely True

The Green Party’s formal policy framework, under Polanski’s leadership, contains no numerical cap on immigration and explicitly targets the progressive reduction of immigration controls. The long-standing Policies for a Sustainable Society (PSS) logic would, if implemented, effectively bar restrictions on migrants from most major source countries (India, Pakistan, Nigeria) because they have far lower economic power than UK residents. However, neither Polanski nor the party uses “open borders” or “unlimited immigration” as language, and the party states it supports a “fair and well-managed migration system.” The claim is substantially accurate in pointing to the effect of stated policies — no numerical limit — but is somewhat overstated in implying this is a deliberate or explicit design choice.

Claim

“The UK Green Party will implement effectively unlimited immigration” (focused on Zack Polanski’s era as leader)

Context

Zack Polanski became sole Leader of the Green Party of England and Wales on 2 September 2025, winning the leadership election with 84.1% of the vote (beating incumbent co-leader Adrian Ramsay and MP Ellie Chowns). He had been Deputy Leader since September 2022. His stated approach is “eco-populist,” linking inequality, climate and social justice. He has not changed the party’s Policies for a Sustainable Society (PSS) immigration chapter, which was last amended in Autumn 2017.

Evidence

✅ The Green Party has no numerical cap on immigration in any policy document

The Green Party’s 2024 general election manifesto — the most recent full policy document — contains zero mention of any numerical target, cap or ceiling on immigration. This contrasts explicitly with statements from all other major parties, including Labour leader Keir Starmer’s “Read my lips — I will bring immigration numbers down.”

The manifesto (pages 20–21, “Sharing a Fairer, Greener Welcome”) states the party’s goal is:

“How we treat people who have chosen the UK as their home says a great deal about our values and national character. Greens are proud that we are a country forged by migrants and welcome the economic and societal contributions that immigrants and refugees make to British society.”

The manifesto makes no mention of reducing or capping total immigration numbers.

✅ Official party policy (PSS) explicitly targets reducing immigration controls

The Green Party’s Policies for a Sustainable Society (PSS), migration chapter (MG), is the authoritative long-term policy document. Key provisions:

MG300 (Medium-term policy):

“We will work to achieve greater equity between the UK and non-Western countries. In step with this, we will progressively reduce UK immigration controls.”

MG203 (Principle):

“Richer regions and communities do not have the right to use migration controls to protect their privileges from others in the long term.”

MG204(c) — when migration restrictions ARE permitted:

Communities can restrict migration when “the prospective migrants have, on average, equal or greater economic power than the residents of the recipient area.”

This is crucial: under MG204(c), restrictions are only permitted when migrants are as wealthy as or wealthier than UK residents. For the major source countries, income is dramatically lower (see below), meaning the PSS logic would effectively prohibit restrictions on migrants from these countries.

MG205:

“Preference should not be given to those with resources or desirable skills.” — This explicitly rules out a points-based immigration system.

✅ The 2024 manifesto removes multiple existing immigration restrictions

The Green Party 2024 manifesto commits to:

No compensating restrictions or caps are proposed.

✅ Massive income incentive — PSS logic would prevent restrictions on most source countries

The PSS (MG204c) only allows immigration restrictions when migrants have “equal or greater economic power.” World Bank GNI per capita data (2024) shows:

India and Nigeria are among the top source countries for UK immigration. If PSS policy were implemented, the UK could not restrict immigration from these countries under MG204(c), since their citizens have far less economic power than UK residents.

The economic incentive to migrate to the UK from these countries is enormous. Even if only a tiny fraction of eligible populations in source countries chose to migrate, this would represent enormous numbers in absolute terms. For context, India alone has a working-age population of approximately 900 million.

🟡 Under Polanski, the party describes itself as supporting “fair and well-managed migration”

In March 2026, under Polanski’s leadership, Green Party Deputy Leader Rachel Millward said in response to Labour’s immigration reforms:

“That’s why we support a fair and well-managed migration system alongside serious action on the cost-of-living crisis.”

This is the language the party uses when pressed. It suggests some degree of management is envisaged. However, the statement does not indicate what “management” means in practice — no numerical targets, caps, or limits are specified anywhere in party documents.

The same statement explicitly condemned Labour’s policies as “a rehash of an old BNP policy,” reinforcing that the party considers mainstream immigration restriction to be extreme.

🟡 Polanski has not explicitly called for “open borders”

There is no recorded statement by Polanski explicitly calling for “open borders” or “unlimited immigration.” His public statements emphasise opposition to anti-migrant rhetoric and support for migrants’ rights, but do not frame immigration policy in unlimited terms.

In his leadership campaign (2025), Polanski said the Greens needed to challenge Reform UK’s political narrative — this was primarily about tone and framing, not specific policy changes.

His December 2025 visit to Calais (where he witnessed French police slashing migrants’ tents) was framed as a humanitarian concern, not a policy statement.

Under Polanski, the party’s stance has emphasised: Labour is wrong to restrict immigration; migrants contribute positively; the UK is “a country forged by migrants.”

🟡 PSS does permit some limited restrictions — ecological and public safety

The PSS does preserve some restrictions:

• MG207: “Regions or communities must have the right to reject specific individuals on grounds of public safety.” (Individual-level, not numerical)
• MG204(a): Restrictions permitted if “ecology of the recipient area would be significantly adversely affected”
• MG204(b): Restrictions permitted for protection of indigenous peoples’ traditional lifestyles

These are narrow exceptions. None constitute numerical limits on immigration from specific countries, and none would apply to the UK’s current situation in any meaningful sense.

❌ The party does not use the language “unlimited immigration” or “open borders”

The Green Party consistently avoids “open borders” language. It frames its position as humane, practical and rights-based. The party would dispute the characterization “unlimited immigration” on the grounds that:

1. It supports “management” of migration
2. It retains public safety exceptions
3. Its long-term goal is a world where less migration is necessary (MG100, MG200)

The PSS opening (MG100) states: “The Green Party’s long-term global vision is of an international economic order where… the quality of life… is such that there is less urge to migrate.” This implies the party views open migration as a transitional state, not a permanent goal.

Summary

The Green Party’s formal immigration policies, unchanged under Polanski, contain no numerical cap on immigration and explicitly target the progressive reduction of immigration controls (PSS MG300). The PSS logic (MG204c) would effectively prohibit restrictions on migrants from countries with far lower incomes than the UK — covering virtually all major source countries. The 2024 manifesto removes multiple existing restrictions without introducing compensating limits. The enormous income differential between the UK and major source countries means the Green Party’s policies would, in practice, create very strong economic incentives for large-scale migration with no meaningful numerical limit.

The claim is Largely True: the policies would, if implemented, result in effectively unlimited immigration (no cap, progressive reduction of controls, removal of restrictions on major source nations). The qualification is that the Green Party does not describe its policy in these terms and does include narrow safety-valve exceptions.

References

1. Green Party PSS — Migration Chapter (MG)

• Source: Policies for a Sustainable Society: Migration (MG100–MG454)
• URL: https://web.archive.org/web/20240601000000/https://policy.greenparty.org.uk/mg/
• Publisher: Green Party of England and Wales
• Date published: Last amended Autumn 2017 (major revision January 1990)
• Date accessed: 2026-03-09
• Evidence: green-party-pss-migration/2026-03-09_19-50-23/

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2. Zack Polanski — Wikipedia

• Source: Wikipedia biography of Zack Polanski
• URL: https://en.wikipedia.org/wiki/Zack_Polanski
• Publisher: Wikipedia
• Date published: Ongoing; accessed March 2026
• Date accessed: 2026-03-09
• Evidence: zack-polanski-wikipedia/2026-03-09_19-48-35/page.pdf

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3. Green Party 2024 General Election Manifesto

• Source: “Real hope. Real change.” — Green Party 2024 General Election Manifesto
• URL: https://greenparty.org.uk/about/our-manifesto/
• Publisher: Green Party of England and Wales
• Date published: June 2024
• Date accessed: 2026-03-09
• Evidence: green-party-manifesto-2024/2026-03-09_19-48-49/

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Note: Full immigration/migration content is on pages 20–21 of the long-form PDF (downloadable from the manifesto page).

4. Green Party statement on Labour immigration reforms (Polanski era)

• Source: “‘Rehash of an old BNP policy’ — Greens slam Labour immigration reforms”
• URL: https://greenparty.org.uk/2026/03/05/rehash-of-an-old-bnp-policy-greens-slam-labour-immigration-reforms/
• Publisher: Green Party of England and Wales
• Date published: 5 March 2026
• Date accessed: 2026-03-09
• Evidence: green-party-immigration-statement-2026/2026-03-09_19-49-30/page.html

5. World Bank GNI per capita comparison

• Source: World Bank — GNI per capita, Atlas method (current US$)
• URL: https://data.worldbank.org/indicator/NY.GNP.PCAP.CD?locations=GB-IN-PK-NG-RO
• Publisher: World Bank
• Date published: Data as of 2024 (published February 2026)
• Date accessed: 2026-03-09
• Evidence: worldbank-gni-comparison/2026-03-09_19-50-10/page.pdf

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