The Ministry of Planning and Investment responded to this issue as follows:

The negotiation of the contract is carried out in accordance with the provisions of Article 19 of Decree No. 63/2014/NĐ-CP:

"1. The first-ranked contractor is invited to negotiate the contract. In the case where the contractor is invited to negotiate the contract but does not attend or refuses to negotiate the contract, the contractor will not be given back the bid security.

2. The contract negotiation must be based on the following basis:

a) Evaluation report of the bidding dossier;

b) The bidding dossier and the documents clarifying the bidding dossier (if any) of the contractor;

c) The invitation to bid dossier.

3. Principles of contract negotiation:

a) Do not negotiate on the contents that the contractor has bid in accordance with the requirements of the invitation to bid dossier;

b) The contract negotiation must not change the bid price of the contractor after fixing errors, correcting deviations, and deducting the discount value (if any). During the evaluation of the bidding dossier and the contract negotiation, if it is found that the quantity stated in the invitation to bid quantity table is less than that in the design dossier, the inviting party shall require the contractor to supplement the missing work quantity based on the bidding unit price; in case there is no unit price in the bidding dossier, the inviting party shall report to the owner for consideration, and decide on the application of the unit price stated in the approved estimate for the quantity of work missing compared to the design dossier or the unit price of another contractor that has passed the technical evaluation step if this unit price is lower than the unit price approved in the bidding package estimate;

c) The negotiation of deviations shall be carried out in accordance with the provisions of Point d, Clause 2, Article 17 of this Decree.

4. Content of contract negotiation:

a) Negotiation on incomplete, unclear, or inappropriate details, and inconsistencies between the invitation to bid dossier and the bidding dossier, as well as among different contents within the bidding dossier, which may lead to a rising issues, disputes, or affect the responsibilities of the parties during the contract implementation process.

b) Negotiation on discrepancies identified and proposed by the contractor in the bidding dossier (if any), including proposals for changes or alternative solutions by the contractor if the invitation to bid dossier allows bidding with alternative solutions.

c) Negotiation on personnel for construction and mixed-use packages:

During the negotiation process, the contractor shall not change the key personnel proposed in the bidding dossier to assume positions such as design supervisors, survey supervisors (for construction and mixed-use packages that require the contractor to perform one or two design steps before construction), chief site supervisors unless the evaluation of the bidding dossier extends beyond the prescribed period or due to force majeure, preventing the proposed key personnel from participating in the contract implementation. In such cases, the contractor is entitled to change other personnel, but it must ensure that the intended replacement personnel have equivalent or higher qualifications, experience, and capacity compared to the proposed personnel, and the contractor shall not change the bid price.

d) Negotiation on arising issues during the contractor selection process (if any) with the aim of completing the detailed content of the bidding package.

đ) Negotiation on other necessary contents.

5. During the contract negotiation process, the parties involved in the negotiation work to finalize the draft contract document, specific conditions of the contract, and contract appendices including detailed lists of the scope of work, unit prices, and implementation schedule (if applicable).

6.  In case the negotiation is not successful, the inviting party shall report to the owner for consideration and decide to invite the next-ranked contractor for negotiation; if the negotiation with the next-ranked contractors is also unsuccessful, the inviting party shall report to the owner for consideration and decide to cancel the bidding as stipulated in Clause 1, Article 17 of the Bidding Law.

According to the provisions of Article 65 of the Bidding Law, the contract to be signed between the parties must comply with the contents of the bidding dossier, requirements dossier, bidding dossier, proposal dossier, the result of contract negotiation, and the decision to approve the contractor selection result. For joint venture contractors, all members participating in the joint venture must directly sign and stamp (if applicable) on the contract document.

Therefore, the negotiation and signing of the contract serve as the basis for contract implementation in compliance with the above-mentioned regulations. The implementation of the contract must be based on the terms stated in the signed contract.