Refugee groups and lawyers have described Conservative proposals to strip judges of their powers to rule on asylum seekers’ appeals against deportations as “an attack on the concept of justice and equality under the law”.

In a speech on Tuesday, Chris Philp, the shadow home secretary, said a Conservative government would quit the European convention on human rights (ECHR) and abolish the judicial tribunal system that claimants use to appeal against their removal.

Immigration decisions would instead be made by the Home Office, Philp said, which would allow migrants a quick internal appeal. The Conservatives would also scrap legal aid for all immigration cases, he said.

The policy has dismayed human rights advocates and lawyers. Sile Reynolds, the head of asylum advocacy at Freedom from Torture, said: “Philp’s proposals are nothing short of an attack on the concept of justice and equality under the law.

“For [survivors of torture] and all those seeking protection, the consequences of a wrong decision can be fatal. The independent appeal process and access to effective legal advice are crucial safeguards that stop the government wrongly sending them back into the hands of their torturers.”

Imran Hussain, the director of external affairs at the Refugee Council, said the proposals would remove democratic safeguards. “No British government should be free to mark its own homework when it comes to people questioning unlawful actions,” he said.

Mark Evans, the president of the Law Society of England and Wales, said scrapping immigration tribunals would remove all independent oversight. “This right is central to our justice system and essential for those of us seeking safety. Judges can only act within the law and to accuse them of bias when they cannot respond is damaging and unfair,” he said.

The Immigration Law Practitioners’ Association (ILPA) accused Philp of “fostering a climate of hostility” towards lawyers and the judiciary.

“An independent legal profession and judiciary are fundamental to our democracy … We are therefore extremely concerned that once again senior politicians appear to be fostering a climate of hostility towards immigration practitioners and judges,” it said.

In an address to the right-leaning thinktank Policy Exchange, Philp said the UK had “created a legal system in immigration that hands near-unlimited power to judges to decide individual immigration cases and also the power to shape how the whole system operates through case law”.

He criticised the judiciary, saying some members had worked with “open border campaigners”, and he highlighted a judge who granted a Palestinian family the right to live in the UK after they applied through a scheme originally meant for Ukrainian refugees.

“These cases show immigration tribunal judges handing down decisions that fly in the face of common sense, but they are enabled by the current system,” Philp said.

He also highlighted another judge who had allowed an Albanian burglar with 50 convictions to stay in the UK because his offending was “not very extreme”. “So if your house is broken into by an Albanian burglar, you know which judge you can thank for that,” he said.

Philp said the Tory plans would mean that the vast majority of people arriving in the UK illegally – such as by small boats or in the back of a lorry – would not be allowed to make a claim of asylum.

However, he declined to go as far as Reform UK, which has said it would ignore the principle that guarantees no person should be returned to a territory where their life or freedom would be threatened.

“If a determination was made that [asylum seekers] were genuinely at acute risk in that country of origin … there would be a power for the home secretary to send to a safe third country like Rwanda,” he said. “But I would expect the vast majority of cases of illegal immigrants, to entail return to their country of origin.”

Shabana Mahmood, the home secretary, is replacing the two-tier tribunal system with a single independent appeals body to fast-track cases.

Reform UK is proposing a law that would prevent the Home Office, immigration tribunals and higher courts from considering asylum claims for anyone who has entered the UK via illegal routes.