Australia’s lawmakers, including Treasurer Wayne Swan, are still not convinced that Singapore Exchange’s bid for ASX is in the national interest.

The A$7.8 billion ($10.1 billion) offer for the nation’s main bourse yesterday won the approval of Australia’s competition regulator, overcoming one of several hurdles before getting the go-ahead. It still needs the support of Swan, the Foreign Investment Review Board, the Reserve Bank of Australia, the Australian Securities and Investments Commission, and parliamentarians, several of whom are opposed to the sale.

Yesterday’s approval by the Australian Competition and Consumer Commission “is not a factor for me,” Swan said in an e-mail late yesterday. “I’ll take a very methodical approach. I’ll examine all of the material before me including the material from the ACCC and at the end of the day I will take a decision in the national interest of Australia.”

Singapore Exchange’s bid to win Australian parliamentary approval for its offer for ASX “will be one of the key reform battlegrounds for 2011,” said Rob Oakeshott, one of three independent lawmakers whose support the minority Labor government led by Prime Minister Julia Gillard needs to pass legislation. Even if SGX’s bid wins all regulatory approvals, laws amending the Corporations Act will need to be passed in both houses of parliament.