Complex sentence: The governing People's Action Party (PAP) sought to secure their twelfth consecutive term in office since 1959 in the first election held since Lee Hsien Loong became its Secretary-General.
Split into simpler sentences: The governing People's Action Party (PAP) sought to secure their twelfth consecutive term in office since 1959. This would be the first election since Lee Hsien Loong became its Secretary-General.