During the procurement process the Authority will have based its evaluation of the bids at least in part on an assessment of the abilities of the Sub-Contractors to deliver the proposed services. If the Contractor were free to change its Sub-Contractor at its sole discretion then this could threaten the validity of the whole procurement process. However the Contractor and its funders will clearly need to be able to replace a Sub-Contractor if it is failing to perform its obligations. The Contract will therefore usually include provisions which strike a balance between these two considerations.
The WIDP Contract (Clause 81.3) requires the Contractor to seek the Authority's consent before appointing a Sub-Contractor. The Authority has twenty Business Days in which to respond. The Authority cannot unreasonably withhold its consent but equally the WIDP Contract (Clause 81.6) sets a list of grounds for the Authority to refuse consent.
Given the complexity of the issues and the legal drafting in relation to the appointment of a new Sub-Contractor the Contract Manager should seek input from the legal department as soon as a request for consent is received from the Contractor. This approach should be clearly set out in the Contract Management Manual.