"On the front burner" is a commonly used idiom which means that a particular issue or project is receiving top priority or immediate consideration. Synonyms for this idiomatic expression can include "top of the list," "highest priority," "at the forefront," "at the top of the agenda," "in the spotlight," or "under active consideration." These phrases all convey the idea that a particular task or issue is of utmost importance and requires immediate attention. They can be used interchangeably with "on the front burner" in various contexts such as business meetings, project management, or politics. The key is to choose a synonym that accurately conveys the urgency and importance of the matter at hand.