The Sibu by-election in Sarawak on 16 May is a test on several fronts. A win for the Barisan Nasional, which appears likely, would put the Barisan within striking range of taking back its two-thirds majority in the national parliament. Beyond that is the old rivalry between two sworn enemies – the Sarawak United Political Party for the ruling Barisan Nasional coalition and the Democratic Action Party for the opposition Pakatan Rakyat banner. As with all of the by-elections that have occurred since the national elections of March 2008, it is being hard fought, even harder perhaps.