Metadata retention accounts for up to 90 per cent of police counter terrorism investigations and needs to be legislated, Australian Federal Police Commissioner Mark Colvin warned on Thursday.

Speaking at a press conference alongside Prime Minister Tony Abbott about the government’s mandatory metadata retention scheme, Mr Colvin said it was a “basic foundation building block in investigations in this country”.

• Explainer: what is metadata?
• How you could end up paying the govt’s ‘spy tax’

The legislation will be introduced in parliament later this month and will seek to force telecommunications companies to retain information about customer activities for two years.

The comments come after Telstra last week said the proposal would make telcos highly attractive targets for hackers looking for customer information.

Telstra’s chief information security officer Mike Burgess said the company would have to put extra measures in place if the legislation was successful.

Prime Minister Tony Abbott with AFP chief Mark Colvin. Photo: AAP

“If [you were] that way inclined as a hacker, you would go for that system because it would give you the pot of gold, as opposed to working your way through our multitude of systems today to try and extract some data,” Mr Burgess told the ABC.

But Mr Abbott said it was “absolutely critical” the legislation was approved to protect the Australian public after attacks like the Sydney siege.

The government is now waiting on a parliamentary committee report on the legislation due by the end of the month.

The prime minister has written to opposition leader Bill Shorten and wants Labor’s support to push it through both houses by the week of March 16.

Mr Colvin dismissed concerns police would be given unlimited powers to monitor Australians’ phone activity, saying it wasn’t as broad as speculated.

“It’s not giving police or security agencies any new powers. It’s about providing certainty about how long the industry retains data.”

“I don’t want to rely on luck for my officers to be able to access the information they need to be able to solve some of the most serious crimes this country has seen.”