How does the politicisation of trade policy affect the lobbying strategies chosen by interest groups? Several studies have shown that business associations tend to focus more on inside lobbying and citizen groups more on outside lobbying. We argue that politicisation makes this difference in lobbying strategy even more pronounced. Facing an issue that is contested and publicly salient, we should see business actors move even more toward inside lobbying and citizen groups move even more toward outside lobbying. We test this argument using a unique combination of evidence from a survey with 691 interest groups and an analysis of Twitter usage with respect to the Transatlantic Trade and Investment Partnership (TTIP) by 993 interest groups. The empirical evidence largely supports our argument. By making and testing this argument, we contribute to the literatures on the politicisation of trade policy and interest group strategies.