Ofgem has proposed to revoke a provisional order imposed on Npower forcing it to cooperate fully in a collective switching trial.

The regulators said it is “satisfied” the supplier has now complied with the order, meaning it is no longer necessary. Interested parties have until 15 April to submit any objections.

Ofgem issued the order on 24 September after Npower refused to allow 100,000 of its customers to participate in the trial in which consumers who had remained on a default tariff for at least three years were offered a cheaper deal negotiated on their collective behalf.

At the time, Npower expressed disappointment, saying it had not been able to agree some “detailed points” with Ofgem at the “final hour”.

Three days later on 27 September the regulator filed for an injunction in the High Court compelling the supplier to comply with the terms. This was granted on 4 October. Ofgem decided to confirm the order on 26 November.

Npower applied to the court for a judicial review into the matter which was thrown out on 21 December. In his ruling, the presiding judge rejected all of the grounds on which the supplier lodged an appeal, saying he “accepted substantially” the arguments of Ofgem.

The switching trial took place during the autumn. It was a follow on to a smaller trial held over the preceding summer, the final results of which were published in December.

Npower has declined to comment further.