A side deal in the free-trade agreement with the United States that the Howard government negotiated nearly a decade ago is a wildcard as the government deals with divisions in its ranks over Archer Daniels Midland's $3.4 billion takeover offer for GrainCorp, the biggest grain handler in eastern Australia.
The free-trade agreement issue is believed to have surfaced last week, and it appears to increase the pressure on the government to wave the takeover through.
It commits the government to advise the US government if there are concerns about a US takeover bid for an Australian company, to give the US the option of opening up direct government-to-government talks, and to allow "sufficient time" for it to do so.
The deadline for a decision on Archer Daniels Midland's bid for GrainCorp was extended to December 17 in October by the Treasurer, Joe Hockey, and is now three weeks away.
Hockey hinted on Thursday, however, that the decision is close, saying it was "not too far off".
He cited the size and complexity of the takeover when he gave himself more time, but by October it was already clear that the Coalition was divided about the takeover proposal.