The United Nations’ refugee agency has sharply criticised the UK’s plans to limit asylum rights, saying they risk breaching the UK’s international legal commitments and undermining global efforts to help refugees.

The UNHCR published the criticisms in an unusually forthright statement and detailed 35-page opinion ahead of Tuesday’s Queen’s Speech in which the government will set out its legislative agenda for the year. This includes a controversial New Plan for Immigration to be written into law, which would discriminate against asylum seekers arriving in the UK via clandestine routes.

The international body’s criticisms are the latest to raise concerns about the compliance of the proposals with UK obligations under the 1951 refugee convention. The convention is normally interpreted as barring countries from discriminating against people who have broken immigration laws to reach their territory before lodging an asylum claim.

“These plans threaten to create a discriminatory two-tier asylum system, undermining the 1951 Refugee Convention and longstanding global co-operation on refugee issues,” said Rossella Pagliuchi-Lor, the UNHCR’s representative in the UK. But It was not too late for a rethink, she added: “We’re ready to work with the UK on alternative reforms,” Pagliuchi-Lor said

The UK was until December part of the EU’s Dublin conventions, under which asylum seekers can be returned to other safe countries through which they have travelled. The 1951 convention imposes no obligation on claimants to seek asylum in the first safe country they reach.

Priti Patel, the home secretary, first put forward her reforms on March 24 as part of efforts to address the surge in clandestine migration across the English Channel by people seeking asylum in the UK. The Home Office has considered a range of controversial options to curb arrivals via this route, including wave machines in the English Channel to drive boats back into French waters. There were 8,420 asylum claims in 2020 by people who had made clandestine Channel crossings.

Patel’s proposals would prevent people who claim asylum after passing through other safe countries, such as France, from having immediate recourse to the UK’s asylum system. The Home Office has already begun writing to asylum seekers who have passed through other safe countries to inform them that their claims are being delayed while the UK assesses whether they can be returned to another country.

The government has insisted its plans are “fully in line” with the UK’s international and legal obligations and has reiterated its contention that claimants should seek asylum in the first safe country they reach.

“We are reforming the asylum system so it is fair but firm, welcoming those who come to the UK through safe and legal routes while cracking down on criminal gangs that facilitate these dangerous and illegal journeys,” the government said.

Pagliuchi-Lor said the proposals would be “expensive and hard to implement”.

“We can’t see them deterring movements of desperate people and the human consequences will be real and harmful,” she said.

The UK has said it will launch a new global resettlement scheme to allow persecuted groups a legal route to the UK. But no such route is currently operational.

The UNHCR’s statement follows other condemnation in the past week, including from the Law Society, representing solicitors, which said the plans were a “serious threat to the rule of law”. The Bar Council, representing barristers, also said proposed limits on appeals risked creating “serious unfairness”.