Polish operator Play (P4) said it could sue the country’s government over plans to change the rules of its long-running 4G auction.

The lengthy auction hit controversy after the government issued a proposal to stop the process prematurely, which has been running since February, after 115 auction days, meaning it could end as early as October.

After the operator first hit out at the plans earlier this month, P4’s Greece-based parent company Olympia Development has now taken its protests a step further, stating to Bloomberg that halting the auction may cause an “irreversible infringement of interests” for the unit, and “tangible damages” of up to €500 million.

P4’s CEO Jorgen Bang-Jensen told the publication it is “strongly in favour of a quick sale of frequencies to operators” before adding that “the country may get into long lasting legal disputes that would be harmful for the whole industry” if the auction is cut short.

The process has seen the country’s four bidders repeatedly raise prices for licences, with offers totalling approximately PLN7.39 billion ($1.95 billion) as of 22 September, with the sum now almost rivaling prices for licences in France and Germany, despite considerably lower revenue per customer in Poland.

Other operators, including Polkomtel’s Plus and Deutsche Telekom’s T-Mobile Polska, have also hit out at the government’s proposals, with the former claiming that the rules go against regulations determining auction terms as well as other laws.

The country’s regulatory head Magdalena Gaj questioned this month whether “the market is serious about buying these frequencies” after 400 rounds of bidding.

Bang-Jensen however reiterated the company’s calls for the auction to be cancelled, and then reopened, “with a possible outcome in weeks”.

Olympia added that “it’s determined to seek an amicable solution with the Polish government, which will support quick spectrum allocation without violating the rights of the participants of the ongoing auction”.

The government has still not made a final decision on the matter, according to reports.