Home Affairs Minister Tony Burke alone decided to postpone a major speech unveiling tougher migration rules, Deputy Prime Minister Richard Marles says despite reporting he led a top-level plot pumping the breaks on the measures. Mr Burke was forced to delay his speech as a result. Mr Marles on Friday refused to “go into cabinet discussions”, insisting there was no plot and Mr Burke’s last-minute delay was “not unusual”. “We’re working through what is a complex policy but a policy where we’re making significant progress,” Mr Marles said. “That’s why we’ve reduced the net migration rate by 45 per cent.”