ACT Labor's new procurement laws passed on Thursday with the support of the Greens, despite a last ditch plea from the Master Builders Association ACT and the Canberra Liberals to delay the implementation by six months.

The legislation would require businesses tendering for ACT government work to be audited to ensure their compliance with industrial relations and employment laws, and that they adhere to a secure local jobs code. It will apply to contracts for construction, cleaning, security and traffic management from January 15 and will be extended to other industries later.

The actual code will be set later via disallowable instrument, but a draft shows it would extend the rights of unions in workplaces.

A submission from the Department of Jobs and Innovation said while any requirement in the code that is inconsistent with Commonwealth laws would be invalid, the conflicting measures may create confusion for contractors.

"Broadly, the department is concerned about provisions or requirements in the package that are inconsistent with Commonwealth laws, such as the general protections provisions of the Fair Work Act 2009, noting the stated policy intent of the ACT Government that there is and should be no conflict between the laws," the submission said.

"Notwithstanding this stated position, contractors across industry, initially security, cleaning, traffic control and construction, would be required by the Secure Local Jobs Code to act inconsistently with these protections."

The inconsistencies include a provision in the code that would apparently require an employer to discriminate between employees on the basis of union membership, contrary to the Fair Work Act.

One clause would require businesses to provide union delegates with access to facilities, and paid time for representation and training purposes. The department also said the code requires businesses to recognise the representative of unionised employees only, which disadvantages non-union members.

Another clause requires businesses to allow union meetings with workplace delegates at a time convenient to them, and to provide new starters with union application forms.

The department also contends the code clashes with the Federal Building Code by requiring companies to indicate support for union membership by facilitating elections for union delegates, allow delegates paid time to talk to other employees about industrial relations matters during work hours and to attend union training and tribunals, as well as access to meeting rooms, photocopiers, phones and internet.

"[This] would result in Building Code covered entities failing to protect freedom of association, in particular, that persons are not discriminated against in respect of benefits in the workplace because they are, or are not, members of a union," the submission reads.

The department said while businesses could seek an exemption from one or more requirements at the code, there was no guarantee it would be provided.

"It is clear that contractors across industry, of varying size, that are covered by the Fair Work Act and/or the Building Code would be placed in a difficult position where the onus is on them to identify conflicting requirements between the Secure Local Jobs Code and their obligations under Commonwealth laws, gather evidence of the conflict and then seek an exemption," they said.

A spokeswoman for Employment Minister Rachel Stephen-Smith said the government was conscious of the need to avoid conflict with federal laws.

"For the avoidance of doubt, an exemption may be granted from a requirement in the code if the Secure Local Jobs Code registrar is satisfied that the requirement would result in non-compliance with a Commonwealth law," she said.

"The government is currently considering feedback received during the recent consultation process, including feedback from the Commonwealth government. We are working to finalise the code as a disallowable instrument as quickly as possible."