Complex sentence: Mayfair, Belgravia and Knightsbridge rank among Europe's wealthiest residential districts but around half the electorate are in the more socially mixed areas of Bayswater and Pimlico, or the former council estates of Westminster proper.
Split into simpler sentences: Mayfair, Belgravia and Knightsbridge rank among Europe's wealthiest residential districts. Around half the electorate are in the more socially mixed areas of Bayswater and Pimlico, or the former council estates of Westminster proper.