Labor will review its support for the government's controversial data retention legislation just four months after it helped pass it into law, as ongoing internal ructions over the issue resurfaced at the party's national conference.

The move comes at a testing time for Labor leader Bill Shorten following his surprise announcements this week on new asylum seekers and renewable energy policies, and a bruising appearance at the Royal Commission into Trade Union Governance and Corruption this month.

Second thoughts: Labor will review its stance on mandatory data retention laws. Credit:Alex Ellinghausen

An amendment to review Labor's policy on data retention passed the conference floor on Friday, citing concerns over the range of government agencies able to access citizens' metadata without a warrant, and concerns about journalists' protection of sources.

Under the Telecommunications (Interception and Access) Amendment (Data Retention) Bill, passed in March, Australian telecommunications providers such as Telstra and Optus are required to store customers' metadata – such as the time, origin and destination of emails, phone calls, texts and web activity, but not the content – for two years for intelligence-gathering purposes.