Part 3: Award of public contracts and procedures Exclusions and modifications Section 31: Modifying a section 19 procurement
There will be times when changes need to be made to the "terms of a covered procurement" (defined at subsection (7)). Subsection (1) sets out when it is permitted to make changes to the terms of a covered procurement during an open procedure (i.e. prior to tenders being received), and during a competitive flexible procedure (i.e. before the deadline for submitting a request to participate or before the deadline for submitting the first or only tender). This aims to strike an appropriate balance between permitting changes to the terms of a covered procurement without allowing contracting authorities to change the goal posts after suppliers have already relied on that information.
	Subsection (2) also provides for "non-substantial" modifications to be made after requests to participate or initial tenders are received in a (multi-staged) competitive flexible procedure. These must be made before the deadline for submitting final tenders.
	For light touch contract procurements (where contracting authorities benefit from greater freedoms), modifications of any type are allowed before the submission of tenders.
	Subsection (3) defines "substantial" modification as any change that would likely a) permit suppliers not participating to submit a tender or b) change the composition of participants had the modification be contained in the tender notice or tender documents. In essence, the section mandates that a substantial change is one that would likely impact the market response to the procurement.
	If a modification is made, then subsection (4) requires contracting authorities to consider revising the time given to suppliers to modify their tenders before they are submitted.
	Subsection (5) requires transparency of the modifications made under subsection (1) through the revision and reissue of the tender notice and any associated tender documents that were affected by the changes.
	Similarly, if the modification was made under subsection (2), subsection (6) requires a contracting authority to notify those remaining in the procedure (since it is only those remaining in the competition who need to be aware).
	Subsection (7) defines "terms of a covered procurement" and "participating supplier".
	Subsection (8) cross refers to section 43 (switching to direct award).