Some you win, and some you lose. Three weeks ago, Najib Razak was riding high, just back from a chat with Barack Obama in Washington, and celebrating the recapture of Hulu Selangor, one of the parliamentary seats his National Front coalition lost to the opposition in the 2008 general election.

Today it’s the opposition People’s Alliance that is celebrating, after narrowly winning a government-held seat in a by-election in Sibu, Sarawak, one of the two Malaysian states on the island of Borneo.

With up to three years to go before the next general election, neither result makes any difference to the NF’s control of parliament. But both offer insights into the state of the voters’ minds as the prime minister struggles to regain the political initiative and prepares a key economic reform programme.