On the go: Four judges have seen the Supreme Court rule in favour of their appeal to reclaim a pension, in a case that could cost the government £1bn.

As first reported by Pensions Expert’s sister newspaper, the Financial Times, the judgment handed down on Monday stated that the four claimants – who had part-time and full-time salaried appointments – should not have been denied their pensions, even though they did not make a claim to an employment tribunal within three months of completing their part-time work.

According to Browne Jacobson, a law firm representing the four judges, the impact of this judgment is significant. It is anticipated that more than 1,000 judges have brought claims or are relying on the moratorium, and the cost to the Ministry of Justice could reach £1bn.

Part-time judges in fee-paid roles earned their right to a pension in 2013. However, those who held both fee-paid and salaried appointments had time restrictions on when they could claim their pension rights.

To date, these judges have been denied a pension on the basis that time runs from the ending of each fee-paid appointment about which a complaint is made, irrespective of whether they transferred into a salaried appointment.

The appellants argued that their claims were not made out of time, on the basis that the less favourable treatment continues up to and including the point of retirement, and that the correct question to pose was when the less favourable treatment finally occurred, the law firm stated.

Caroline Jones, senior associate at Browne Jacobson, said: “The appellants are delighted by the judgment and that equal treatment has finally been achieved.

“This judgment means that fee-paid judges who were subsequently appointed full-time salaried members of the judiciary will now be entitled to pensions in respect of their former part-time service.”

The Ministry of Justice has been approached for comment.