The Canberra Liberals say that long-service leave is a ''redundant'' idea for modern workers.

The Opposition's industrial relations spokeswoman Vicki Dunne told the Legislative Assembly yesterday that the entitlement to long-service leave was ''dubious'' and a throwback to early colonial days.

Mrs Dunne made her remarks while opposing a bill for portable long-service leave for security workers.

Industrial Relations Minister Chris Bourke brought on the bill, which passed with Greens support yesterday, aimed at allowing Canberra security guards to take accrued long-service leave entitlements from job to job.

The government has a policy of taking long-service leave entitlements to what it deems to be contract-dominated and low-job security sectors such as security and the community sector.

Dr Bourke said he was trying to bring fairness to workers in low paid or high staff turnover jobs.

''This is one further step in this government's resolve to bring fairness to all workers in the territory,'' he said.

But Mrs Dunne said she had a number of problems with the legislation, arguing the scheme would only capture a tiny number of the 2500 claimed by the government, expose a lack of cross-border arrangements, and create more red tape for businesses and several technical loopholes.

The Liberals frontbencher then launched her attack on the idea of long-service leave.

''The concept for long-service leave is a reward for loyalty of service to an employer and is unique to Australia and New Zealand and was established in our early colonial days,'' Mrs Dunne said.

''In those days it was considered reasonable for citizens to be able to sail home to England or Ireland or from wherever they came from [and] that they could do this in the knowledge that their job would still be there when they returned.

''So long-service leave was envisaged in Australia and New Zealand to allow people to return home on a boat.

''So in a sense, it is a real and intended purpose now redundant for many obvious reasons.

''Even from that viewpoint … it is dubious to think that workers remaining in an industry, let alone [with] a single employer, should be able to accumulate long-service leave.''

Support from the ACT Greens came despite the defeat of the crossbench party's amendments to enforce a start-date on the bill.

Greens industrial relations spokeswoman Amanda Bresnan said portable long-service leave would be an improvement for an industry where workers ''often did it tough''.

''The Greens want to see these improvements start as quickly as possible, and we're concerned the government is unnecessarily delaying its start.

''I moved amendments to guarantee a [October 1] starting date, but unfortunately the other parties did not agree.''