Downing Street has confirmed a plan to allow lower courts to roll back EU legal rulings following Brexit, a plan that prompted concerns that it will become easier to challenge European standards in areas such as workers’ rights and the environment.

Under plans made by Theresa May, the incorporation of all EU case law made by the European court of justice into UK law after departure would have left the supreme court as the only body able to overturn these decisions.

But asked about reports that Boris Johnson had ignored concerns from some ministers and decided to allow lower courts the same power, his spokesman confirmed that this would be part of the new withdrawal agreement bill.

The revised bill, which puts Johnson’s Brexit plan into law, is due to be published imminently, and will face its first vote from MPs on Friday, when it is due to have its first and second reading.

The spokesman said: “The bill will ensure that the supreme court is not the only institution able to consider retained European court of justice rulings. This is an important change, which will ensure that we do not face a legal bottleneck and inadvertently stay bound by EU rulings for many years.

“We will take back control of our laws and disentangle ourselves from the EU’s legal order, just as was promised to the British people.”

Asked if this would make it easier for rights such as those on employment to be rolled back, the spokesman said: “These will be matter for British courts. In relation to workers’ rights, there is a commitment by the government in its manifesto, which will be honoured in full, to ensure that we protect and enhance workers’ rights. And that will be done in UK law.”

It is understood that legislation on maintaining workers’ rights will form part of the Queen’s speech, the outline of the government’s legislative plan, which will take place on Thursday following the state opening of parliament.