Abu Dhabi’s national oil company has made a big bet on the future of gas with a $36 billion bid for Santos, setting up a major test for Labor over the ownership of assets critical for Australia’s energy security.

The deal would hand shareholders in the ASX’s second-largest oil and gas producer almost $30 billion in cash, but has been met with a lukewarm reception from investors and the South Australian government, where Santos was founded 71 years ago and remains headquartered.