Utilize the input text as a context reference, choose the right relationship between Grocon and construction from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

The revival of the commission is part of a campaign against the militant construction union by the government, which includes support for developer Grocon and building materials group Boral in their battles with the union and the Heydon royal commission.

Answer: industry