Vodafone UK became the second operator in the country to take legal action against regulator Ofcom in a row over an increase in spectrum prices, a move which could spur other operators into action, The Register reported.

The operator followed in the footsteps of rival EE in the row relating to rises introduced by Ofcom at the government’s request in 2015, the news site said. The move trebled the annual licence fees of many operators, taking the total annual payment to £200 million.

Legal challenges could ultimately see the UK government forced to refund up to £300 million in total.

Operators sought a judicial review regarding the increases in November 2017: the UK Court of Appeal ruled in their favour, claiming Ofcom’s move was not consistent with European laws covering infrastructure investment.

In late 2017, BT and mobile subsidiary EE successfully sued Ofcom to recover the fees, The Register explained, stating the win enabled EE to shed £50 million per year from fees covering its 900MHz and 1800MHz spectrum.

The news site added a preliminary hearing in the Vodafone case has already been heard by the UK’s High Court, with a full arguments due to be presented in 2019.