Complex sentence: As a New Labour insider, he became widely known for being a political advisor and spin doctor and his role in two political scandals, "Lobbygate" and "Smeargate".
Split into simpler sentences: As a New Labour insider, he became widely known for being a political advisor and spin doctor. At present he is best known for his involvement in a number of political scandals including the "Lobbygate" and "Smeargate".