Tony Abbott is stepping up the government's push for laws compelling phone and internet firms to keep customer metadata, calling such data "absolutely critical" to fighting child pornography online.

Ahead of a major statement next week about the need for further national security reforms, Mr Abbott will on Wednesday broaden the government's case over so-called data retention, which police say is vital to combating terrorism but also a wide range of crimes including child exploitation.

"We know that access to metadata has played a role in preventing and investigating terrorism offences. But it's also vital to investigating major crimes that destroy lives in this country," Mr Abbott will say, according to notes distributed by his office.

"And no crime is more abhorrent than crimes against children."