Eritreans were the most common nationality among small boat migrants in the 12 months to June, accounting for 18% of arrivals, according to House of Commons Library figures. Over the same period, more than 5,800 Eritreans arrived via the Channel, while only seven were returned to Eritrea from the UK. A further 244 Eritreans were returned to other countries, the Home Office said.
Mahmood said: "Eritrea has had every chance to accept the return of criminals and those with no right to be in the UK. Unlike other countries, it has refused. My message to the Eritrean government is simple: take back your nationals or face a complete ban on your citizens entering the UK."
From Thursday, Eritrean diplomats are banned from travelling 60km outside London without permission. The Home Office said the restriction mirrors limits placed on British officials in Eritrea's capital Asmara. Fast-track visas for VIPs have also been halted.
The move follows similar threats against Angola, Namibia and the Democratic Republic of the Congo in 2025. Angola and Namibia subsequently agreed to cooperate, while the DRC faced visa restrictions before reaching an agreement with the UK in February. In March, ministers also placed an emergency brake on study visas from Afghanistan, Cameroon, Myanmar and Sudan, and on work visas from Afghanistan.
Just over 100 refused asylum seekers from Eritrea have been deported out of 2,626 whose claims were rejected in the past four years, equivalent to fewer than 4%, according to Home Office figures. Madeleine Sumption, director of the Migration Observatory at Oxford University, said roughly 7,000 asylum applications came from Eritreans, about 8% of the total, with 84% successful on first application.
Refugee organisations have warned against rejecting asylum claims from Eritrea, describing it as a war-torn country where returnees face serious risk. UN experts have said the human rights situation in Eritrea remains dire. One Eritrean asylum seeker told the Guardian that any returnees would "be put in prison and may never be able to get out".
Mahmood said she would "not hesitate to impose further measures on other countries refusing to co-operate". The Guardian reported that India, Pakistan, Nigeria, Bangladesh, Somalia, Egypt and Gabon have been identified as resistant to taking back illegal migrants and could face similar sanctions.