Family First senator Steve Fielding is pressuring the Rudd government to maintain a ban on foreign aid money being used on abortion-related services.
Foreign Minister Stephen Smith has been considering the issue for more than a year and says a decision is "very near".
Mr Smith, who will have the final say on whether to lift the ban, will not give a personal opinion on the issue.
"My personal views will be inextricably interwoven with the decision I make as a minister," he told reporters.
"Which is why I have assiduously avoided indicating what my personal view may or may not be."
Pro-choice Labor MPs have been urging the cabinet to make a decision on the AusAID guidelines, which were imposed by the previous Howard government in return for Senate support from key independent Brian Harradine.
Senator Fielding, a staunch conservative from Victoria, holds one of seven balance-of-power seats in the Senate, making him crucial to the government when it cannot get opposition support for its legislation.
He has asked the prime minister to maintain the ban, though has not made it clear if the issue could sway his support in the Senate.
"Family First opposes abortion and opposes diverting scarce aid funds to this practice," Senator Fielding said in a statement.
"I spoke to the prime minister's office yesterday and stressed that this ban must remain."
Neither Senator Fielding or Prime Minister Kevin Rudd's office could be contacted for comment.
The Australian Greens are trying to make changes to a budget bill to reinstate the AusAID funding for family planning activities.
They want a vote in the parliament but Mr Smith says the issue is one of ministerial discretion.
"This is, of course, a matter effectively for ministerial discretion, so I'm unsure what Senate resolutions may or may not have so far as an impact on that is concerned," Mr Smith said.