Singapore's ruling party sweeps to victory as voters opt for stability / Lawrence Wong retains power in Singapore's general election / Singapore's ruling party headed for clear victory in general elections / Voting closes in Singapore as its long-ruling party seeks a bigger win / Singapore election live: Ruling PAP leads in sample counts / Polls open in Singapore's election as its long-ruling party seeks a bigger win / Singapore election a test for ruling party against rejuvenated opposition / Voting underway in Singapore as its long-ruling party seeks a bigger win