A government minister has been criticised for suggesting “many people” think judges are biased in relation to Brexit.

The business minister Kwasi Kwarteng made the remarks after judges at the court of session in Edinburgh said the suspension of parliament was “unlawful”.

When asked about the Scottish court’s judgment, Kwarteng told the BBC: “Many people are saying – I’m not saying this – but, many people … are saying that the judges are biased. The judges are getting involved in politics.

“I think that they are impartial, but I’m saying that many people, many leave voters, many people up and down the country, are beginning to question the partiality of the judges.”

The Labour MP David Lammy described Kwarteng’s comments as shameful and said the minister had hidden behind “many leave voters …” to attack the judges. He said: “It is completely wrong for government ministers to actively promote and encourage the subversion of the rule of law.

“Politicians must respect the impartiality of judges, even if they do not like the result of their judgments. If they do not, our liberal democratic system will fall apart.”

Simon Davis, the president of the Law Society of England and Wales, said the role of judges was to interpret the laws that parliament passes. “They do so impartially, without fear or favour. We should take pride in our system of justice which provides equality before the law.

“You only have to look around the world to see what happens when the rule of law begins to erode.”

Davis called on influential voices, in politics and the media, “to avoid intemperate language and resolve to protect and promote the rule of law, supporting our judiciary, independent from interference”.

Richard Atkins QC, the chair of the Bar Council, which represents all barristers in England and Wales, said: “The United Kingdom is a country built on the rule of law and the independence of the judiciary is a fundamental pillar of our democracy.

“I strongly urge those in positions of authority not to undermine the courts or judges. Without the legal protections that the courts afford we are all in peril. The Bar Council expects the government to uphold the rule of law in this country.”

Dinah Rose QC, a human rights barrister at Blackstone Chambers, criticised Kwarteng’s remarks as “irresponsible and dangerous”. She said: “Although he has disavowed any personal belief that the Scottish judges are biased, his claim that ‘many people’ think that they are not impartial risks planting the seed of that belief, and has the effect, whether intentional or not, of implying that such a belief is reasonable.”

She added: “Mutual respect between the courts and the government is fundamental to the proper functioning of our democracy. If the government disagrees with the Scottish judgment, it has a right of appeal to the supreme court, which it is currently exercising. If it thinks that the judges were not impartial, it may make that a ground of its appeal. To shy away from such a course, whilst insinuating a lack of impartiality is improper.”

Rose called on the lord chancellor, Robert Buckland QC, to make it clear to all members of the government that such behaviour was “inappropriate, and damaging”.

The former Liberal Democrat leader Menzies Campbell said the comments were ill-judged. “I would expect a government minister to understand the importance of the independence of the judiciary and not make any comments that might undermine public perceptions.”

Susan D Shaw, a managing partner at the Scottish law firm Living Law, said: “The rule of law is the bedrock of our society and affects every aspect of our daily lives. Legal judgments – decisions on the law and proven facts – frequently have profound political ramifications. That does not make them political. Rather, that they are above bluster and bullying tactics.

“This government needs to wake up and grasp the basics of our constitution. The ambit of executive discretion is not infinite. They promised the patently undeliverable and have acted as though they were above the law and beyond accountability. Where we are now is simply reality.”