Except as may be specifically allowed by subdivisions B 1, 2, and 3 of § 2.2-3112, no public employee having official responsibility for a procurement transaction shall participate in that transaction on behalf of the public body when the employee knows that:
1. The employee is contemporaneously employed by a bidder, offeror or contractor involved in the procurement transaction;
2. The employee, the employee's partner, or any member of the employee's immediate family holds a position with a bidder, offeror or contractor such as an officer, director, trustee, partner or the like, or is employed in a capacity involving personal and substantial participation in the procurement transaction, or owns or controls an interest of more than five percent;
3. The employee, the employee's partner, or any member of the employee's immediate family has a pecuniary interest arising from the procurement transaction; or
4. The employee, the employee's partner, or any member of the employee's immediate family is negotiating, or has an arrangement concerning, prospective employment with a bidder, offeror or contractor.