Mr Abbott has written to Opposition Leader Bill Shorten saying he has decided that a further amendment be moved that would require agencies to obtain a warrant to access their metadata for the purpose of identifying a source. "The government does not believe this is necessary but is proposing it accept it to expedite the Bill," Mr Abbott wrote. In return, Mr Abbott is demanding the opposition's support to abort an inquiry into the treatment of journalists' electronic communication data under the counter-terror laws and that the laws be passed by the end of the next week. Mr Abbott requested Mr Shorten respond by 5 o'clock on Monday afternoon. The media union said in a statement the bill was still flawed and should be scrapped rather than amended.

"Journalists cannot allow the relationship they have with a confidential source to be breached, under any circumstance – that is their ethical responsibility," said Media, Entertainment and Arts Alliance chief executive Paul Murphy. "If the surveillance continues and is formally adopted in the Data Retention Bill with or without a warrant, then journalists will be forced to use the tools of counter-surveillance such as anonymisation and encryption to protect their sources." Mr Shorten wrote to Mr Abbott on Sunday warning that he was reserving the opposition's right to move such an amendment. This was an unusual move as it pre-empted the findings of Parliament's joint intelligence committee, which to date has handed down bipartisan recommendations on the new counter-terror laws. But it followed a backlash by the media who were unconvinced by government attempts to assure news outlets that their sources would be protected under broadened metadata laws. A government source said the Coalition has been consulting media companies and considering options to better protect journalists before receiving Mr Shorten's letter. However news organisation will likely want to see further assurances after seeking but being denied a complete exemption for journalists.

Under a warrant process, media companies would want to ensure they were "contestable," and not a "tick and flick," process as one senior media source fears. News organisations would also likely want company lawyers informed of warrant applications and the ability to contest them. Australian veteran political journalist Laurie Oakes said at the weekend that the government's attempts to appease the media companies in a "roadshow" had convinced no-one that journalists' sources would not be targeted. Media CEOs were due to front the parliamentary hearing scheduled on Friday, which if Labor agrees will be cancelled. Currently, law enforcement agencies can access metadata, which includes the time and location of the communication but not their content, without a warrant. Under the proposed amendment, a court would have to give permission for police to use a journalist's telephone or email log if a source or whistleblower was being identified. Just an hour before Fairfax Media revealed the breakthrough, Attorney-General George Brandis was being asked about the issue in Senate question time.

"Does the Attorney-General agree that his data retention bill poses a threat to investigative journalism and more importantly will he commit to postponing parliamentary debate on the bill until after the parliamentary joint committee on intelligence and security has reported on these matters in early June," asked Greens senator Scott Ludlam. "Well the answer to both of those questions is 'No'," Senator Brandis told the Senate. Senator Brandis then attempted to berate Senator Ludlam for being "unaware" of his facts. Senator Brandis insisted the issue had already been addressed by ensuring the Attorney-General of the day would be informed of access to journalists' metadata. "The government also agreed to a recommendation to amend the bill to require agencies to notify the Attorney-General of each such authorisation and further require the Attorney-General to provide a report annually to the Parliamentary joint committee on intelligence and security," he said.

"So, Senator Ludlam, this issue was addressed, it was addressed in a bipartisan fashion." Loading Follow us on Twitter Follow Latika Bourke on Facebook