New legal challenges demanding Parliament has greater control over the Brexit process have been lodged at the High Court, it has been reported.
Four anonymous claimants have joined a judicial review of the Government's EU withdrawal plans, according to The Guardian.
The claims, lodged in the names of people identified only as W, L, T and B, have been accepted for consideration by the High Court, the newspaper said.
The challenges say Britain will remain in the European Economic Area (EEA) and the single market after withdrawal. They insist that parliamentary approval, separate from that to begin Brexit negotiations, is needed to quit the EEA.
One of the barristers involved in the fresh claim, S Chelvan of No5 Barristers Chambers, told The Guardian: "We are seeking a declaration that the UK cannot withdraw from the EEA without the approval of HM Treasury and an act of Parliament.
"These are ordinary working men and women who have decided to make their futures in the UK and wish the UK to be their permanent home. One has mixed nationality, one is a non-EEA national but married to an EEA national. We are trying to highlight the various types of people who will be left in a state of limbo following our withdrawal from the EU."
The Supreme Court is set to rule next month on a Government appeal against a High Court judgment that Parliament must have the final say on invoking Article 50 which formally begins the withdrawal process.
Prime Minister Theresa May has said she wants to trigger Article 50 by the end of next March.