Britain is not safe for migrants because of the risk of deportation to Rwanda, the Irish High Court has ruled.

In a judgment on Friday, Ms Justice Siobhan Phelan said the Irish Government’s declaration of the UK as a “safe third country” to which it could return asylum seekers was unlawful.

She ruled in favour of two asylum seekers who argued the designation was unlawful because it meant they were at risk of onward removal to Rwanda if they were returned from Ireland to the UK.

The declaration will be seen as embarrassing for Rishi Sunak but echoes last year’s Supreme Court judgment that ruled Rwanda was unsafe for migrants.

Home Office sources said the new treaty signed with Rwanda and the Bill, which has been delayed in Parliament, were designed to answer the Supreme Court criticisms with measures to ensure the central African country was safe for migrants.

The Bill is in limbo after the House of Lords defeated the Government on seven amendments on Monday, forcing it back to the Commons on April 15 after the Easter recess.

The move has pushed back potential Royal Assent for the legislation by three and a half weeks and could delay deportation flights to Rwanda from May to June.

‘Unlawful’

The High Court ruling stems from Britain leaving the EU, which meant the Irish Government had to decide whether the UK could be treated as a safe third country outside the EU bloc.

In her decision, Ms Justice Siobhán Phelan held that the designation of the UK as safe, made by Helen McEntee, the minister for justice, in response to the UK’s exit from the EU on January 31 2020, was “unlawful as a matter of EU law”.

By designating the UK as a safe third country, it meant that Ireland could return an asylum seeker to the UK so that their application could be considered there.

It mirrors similar provisions pre-Brexit that Britain had with the EU where it could return migrants to France or other EU states that they had passed through on the basis that they were safe third countries and should have claimed asylum there.

The two legal challenges, which were contested by Ms McEntee, were selected from a large group of cases that alleged the designation of the UK as a safe third country is unlawful because of the risks that arise from a potential transfer to Rwanda.