9. Is there a ban on donations from corporations with government contracts to political parties?

207 Interpretation […]
(2) In this subpart and subparts 4 to 6 of this Part, unless the context otherwise
requires,— […]
New Zealand person means a person who is not an overseas person
overseas person means—
(a) an individual who—
(i) resides outside New Zealand; and
(ii) is not a New Zealand citizen or registered as an elector; or
(b) a body corporate incorporated outside New Zealand; or
(c) an unincorporated body that has its head office or principal place of business outside New Zealand
party donation means a donation (whether of money or of the equivalent of money or of goods or services or of a combination of those things) that is madeto a party, or to any person or body of persons on behalf of the party who are involved in the administration of the affairs of the party, and—
(a) includes,—
where goods or services are provided by a New Zealand person to a party, or to any person on the party’s behalf, under a contract or arrangement at a value less than their reasonable market value, the latter being a value that exceeds $1,500, the amount of the difference between the former value and the reasonable market value of
those goods or services; and […]
Source: Art. 207(2), Electoral Act 1993, (amended 2020)

There no explicit ban on donations from corporations with government contracts.