Neither Stephen Conroy nor the company building the national broadband network will stand by their commitments that it will pass 286,000 premises by this June.
Senator Conroy's evasions come amid reports that NBN Co could announce next week that it will cut its targets by as much as half.
The company will not confirm or deny these reports but twice avoided the question of whether it stood by its targets.
Further delays - which would be the third announced since 2010 - are politically significant as they add to the pressure mounting on the Communications Minister over Labor's media reforms.
During question time in the Senate on Tuesday, Senator Conroy was asked repeatedly whether he stood by his commitment that the network would pass 286,000 premises by the end of this financial year.
Instead of answering the question, he criticised Tony Abbott, saying the Opposition Leader would abandon the network. Liberal senator Simon Birmingham said: ''A June 30 target date, Stephen, do you commit, do you still stand by it mate?''
Senator Conroy avoided the question. ''We have made it clear that there are challenges in meeting those targets,'' he said.
''I am seeking further information from NBN Co about the proposed actions contractors will take to address these challenges.''
The NBN Co also refused to answer the question.