In the UK, following the enactment of the Communications Act 2003, amending the Enterprise Act 2002, the assessment of mergers involving broadcaster and/or newspaper enterprises is subject to – alongside the regular competition standard under the ‘substantial lessening of competition’ (SLC) test – a public interest standard. Under this standard, certain media mergers need to be assessed pursuant to the following considerations: media plurality, broadcasting standard objectives and free expression of opinion grounds. While the statute defines these terms ambiguously, it does provide guidance to the Secretary of State, the competition authority and the courts to decide how the statute is intended to be applied consistently. The paper will analyse how the media plurality test has been applied, some of the considerations of the CMA and OFCOM, and in doing so it will touch on the discretion of the decision making stakeholders.