Federal Labor has agreed to support new metadata laws with amendments.

The government bill, which is expected to pass parliament by the end of next week, forces telecommunications companies to keep two years of customer data, such as the time and length of a phone call.

The Labor caucus on Tuesday spent about 40 minutes debating the bill, with a number of MPs voicing their concerns about its "Orwellian" nature and the lateness of consultation within the party.

The government has agreed to a number of Labor amendments, including better protections for journalists.