The British government’s controversial plan to block undocumented migrants from entering the country on small boats has sparked a heated debate that could determine the result of the UK’s next general election.

British Home Secretary Suella Braverman introduced an illegal immigration bill recently aimed at tackling people crossing the English Channel to reach the UK. The move is dividing Britons.

The UK Government claims the bill is legal but the United Nations and refugee advocacy groups say in breaches international law.

The UN refugee agency UNHCR has said the law would effectively be a “an asylum ban”.

The agency said it would be a “clear breach of the 1951 Refugee Convention”.

The convention defines refugees as those who are seeking refuge from persecution. It also gives them the right to not be sent back home into harm’s way, except under extreme circumstances.

“Most people fleeing war and persecution are simply unable to access the required passports and visas. There are no safe and ‘legal’ routes available to them. Denying them access to asylum on this basis undermines the very purpose for which the Refugee Convention was established,” the UNHCR said.

Spokesperson for NGO Human Rights Watch Emilie McDonnell says the new law won’t work.

“Asylum seekers would be detained en masse; deported to their home country, or Rwanda, or another country the government has deemed safe; and banned from ever re-entering Britain,” Ms McDonnell said.

“They would be stripped of almost all appeal rights. The only exceptions in this sweeping bill are for unaccompanied children, and for people who are subject to specific exceptional circumstances, including those who claim they would suffer serious and irreversible harm if they were removed,” she said.

“Contrary to the narrative the government likes to push, it is not illegal to seek asylum, and it is irrelevant how a person arrived in the UK. What is illegal is the government’s cruel and draconian plan.

“This deplorable proposal is nothing more than an attempt by the government to score political points by using the age-old playbook of stoking fear and division.

“In recent weeks, the UK has been shaken by violent attacks by members of far-right and anti-immigrant groups on hotels housing asylum seekers. Unions have accused the government of emboldening such groups with its inflammatory rhetoric against asylum seekers and other migrants.

“The government knows full well that its proposal is unworkable and ineffective, and that it amounts to a flagrant breach of its obligations under the Refugee Convention and the European Convention on Human Rights,” Ms McDonnell said.

BBC Sports presenter Gary Lineker recently came under fire for comments on social media, in which he likened the language used to set out the government’s immigration plans to “that used by Germany in the 30s”.

Lineker has been condemned by the government but has received support from media figures including Piers Morgan and the former Sky News presenter Adam Boulton.

CEO of the charity Refugee Council Enver Solomon said: “The government’s new legislation ignores the fundamental point that most of the people in small boats are men, women and children escaping terror and bloodshed from countries including Afghanistan, Iran and Syria.”

“We need an approach that replaces the chaos and cost of what we have now and focuses on compassion and competence, creating safe and orderly routes for refugees to reach the UK, such as refugee visas, and always give people a fair hearing so their rights are respected,” he said.

Ms Braverman has defended the new laws but said she could not make a “definitive statement of compatibility” with human rights laws.

Meanwhile, British Prime Minister Rishi Sunak has vowed to fight any legal challenge to the laws while playing down concerns that the bill breached the UK’s obligations under the European Convention of Human Rights.

The new laws come as an increasing number of refugees and migrants fleeing conflict, persecution and poverty are risking the dangerous English Channel crossing between Britain and France every year, sparking a national debate on the issue of migrant crossings

In 2022, 45,755 people crossed the Channel in small boats, according to UK government data. More than 3,000 people have already made the crossing this year.

In December, at least four people after a small boat likely to be carrying migrants capsized in the English Channel. In 2022, 27 people drowned in the freezing waters.

The new laws are the latest move by Britain’s ruling Conservative government’s campaign to stop English Channel crossings.

Last year it announced a scheme which would see asylum seekers deemed to have entered the UK illegally sent to Rwanda to have their asylum claims processed.

The first planned deportation flight to Rwanda was blocked under the European Convention of Human Rights but the policy has been found to be lawful by the UK’s High Court.