The Senate on Thursday night backed the package of changes that give security agency ASIO extended surveillance powers but which critics say could also mean journalists are jailed for revealing information about secret operations in which ASIO officers are permitted to break the law.

The Abbott government's new laws – the first of three tranches of sweeping security changes – were passed with support from Labor but were opposed by the Greens and some crossbenchers.

South Australian independent Nick Xenophon, who voted against the bill, said that "in the end it's going to make it a lot harder for journalists to do their job".

The laws give ASIO agents immunity when they break the law – within limits – while on undercover operations – a protection already given to police officers.

But it also introduces new offences for disclosing information about those operations – including for journalists – with penalties of up to five years or 10 years for an aggravated offence – raising fears that bungles or wrongdoing on such operations will never come to light.

Jail terms for disclosing the identities of ASIO officers is set to jump from one year to 10 years under an amendment pushed by Palmer United Party Senator Glenn Lazarus.

"These brave and hardworking men and women keep Australia safe while at times undertaking extremely dangerous and highly sensitive work," Senator Lazarus said.  "Exposing the identity of an ASIO or ASIS officer not only compromises the safety and security of the officer, it also compromises the safety and security of Australia."

This puts Australia on par with the United States – where the issue made world headlines in 2005 after it emerged that members of the Bush administration leaked the name of CIA officer Valerie Plame.

ASIO would also be empowered to hook into a computer network on just one warrant, dramatically freeing up surveillance powers. Previously they needed separate warrants for individual computers.

The intelligence community has long called for the changes, arguing the failure of the law to keep pace with technology put hurdles in the way of investigations.

George Williams, law professor at the University of NSW, said the disclosure penalty was "extraordinary".

He said many of the provisions updated the law to keep pace with technology but said there were "real concerns" about freedom of the press.

"Imagine a journalist is writing a story about the Sheraton hotel bungle," he said, referring to the 1983 incident in which officers from the Australian Secret Intelligence Service caused mayhem by holding a bungled training exercise in the Sheraton hotel in Melbourne.

He said claims that ASIO could access the whole internet on one warrant under the new "network" rules were "overblown" but said there should be clearer limits on that new rule so that officers could only access the part of the network that was necessary to gather information.