Peter Greste has implored his fellow journalists to continue the fight for press freedom after his imprisonment united the normally “cantankerous and argumentative” profession.

His comments come as the federal government imposes widespread spy laws that make the retention of call and email history compulsory.

Mr Greste avoided any direct comments on Australian politics, but said “the very idea of a free press is under attack”.

• Al Jazeera journos freed pending retrial
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Greste was released from an Egyptian jail in February after 400 days behind bars on charges including spreading lies to help so-called ‘terrorist organisation’ the Muslim Brotherhood.

Global media united behind the cause of freeing Greste and two other Al Jazeera colleagues Mohamed Fahmy and Baher Mohamed, who were arrested and jailed with him.

Fahmy and Mohamed are in Cairo awaiting a retrial, which has been adjourned until April 22.

“I’d be willing to bet that journalists had never united around a single common cause until ours,” he said.

“Whatever happens from here we must not lose that singular voice.”

In a speech to the National Press Club in Canberra today Greste told jokes and shared stories of his incarceration and eventual release.

“I’m still quite bewildered by all of this, I feel like the rabbit in the headlights,” he said. “This is as scary as anything I dealt with in prison.”

But the free speech advocate reserved his harsher criticisms for governments closing down press freedom around the world.

In response to a question related to the Thai leader Prayuth Chan-ocha’s comments on Wednesday that the regime would “probably just execute” journalists who the regime believes are not telling the truth.

Greste pointed out that the relationship between the press and governments was “like a family” where arguments were a natural part of forming a solution.

“This is the way the war on terror is being used in a way to close down the scope of the role of journalists,” he said.

“It comes back to bite you … in the form of terrorism in my view.”