The nation's biggest news organisations will mount a united campaign for sweeping legal changes to protect press freedom after a political storm over raids on journalists, setting out four new defences for those who reveal information in the public interest.

The new safeguards will be put forward on Wednesday after Nine, the ABC and News Corp Australia combined to demand reforms including stricter rules to allow the media to contest search warrants.

ABC managing director David Anderson, News Corp Australasia executive chairman Michael Miller and Nine chief executive officer Hugh Marks.

The changes would give the media more scope to force a judicial review of the search warrants and challenge the power of police to investigate a journalist at the behest of politicians or officials who are embarrassed by leaks to the press.

Nine chief executive Hugh Marks will join ABC managing director David Anderson and News Corp Australia executive chairman Michael Miller at a National Press Club event to set out the four reforms.