BT Group Plc was dumped from a lucrative €458 million ($494 million) European Union contract to handle sensitive communications between the bloc’s governments amid a dispute over the British firm’s potential access to EU secrets following Brexit.

The regulator is planning to determine whether the UK’s net neutrality framework, passed in 2015 under the EU’s Open Internet Regulation, needs to be adjusted to the current environment.

The impact of Brexit on the telecoms industry could be substantial and adverse. BT, Prospect and the Communications Workers Union were so concerned that they sent a joint letter to every BT employee during the referendum to express their deep concern about the potential impact on the company and its employees.

Leaving EU with no deal would heighten risk of contracts being terminated early. BT is facing a post-Brexit battle to maintain access to a number of multimillion-pound EU contracts and avoid the premature termination of a £24m deal with the European parliament.