The phrase "primary importance" means something that is most crucial, essential, or significant. It is the most important thing that needs to be focused on or prioritized. Full definition
What is of primary importance in such decisions is always the best interest of the child. (lisagelman.com)
The characteristics of raw materials are of primary importance in determining the quality of the frozen product. (fao.org)
Some persons in some circumstances discover general traits that seem of primary importance for such understandings, whereas others select different traits as primary. (customwritingservices.org)