in the front line
in the front line(s) (of something)
1. In the leading position of some effort or movement. For over a decade, our organization has been in the front line of advocating for those suffering from poverty. The esteemed neuroscientist has been in the front lines of researching treatments and cures for Alzheimer's disease.
2. In a position wherein one is a likely target of anger, criticism, or judgment. Because call center workers are in the front line, they bear the brunt of customer unhappiness.
See also: front
in the front lineor
on the front line
1. If you are in the front line or on the front line, you are doing the most important and basic work of an organization, often working directly with people. Local authorities are in the front line of providing help. Workers on the front line in hospitals, trains and planes are tired of being abused by members of the public.
2. If you are in the front line or on the front line, you are in a position where you are likely to be criticized or attacked. I'm not happy about putting you in the front line when there's someone out there killing people. She's working in the poorest areas of the city, and she's really on the front line there. Note: The image here is of soldiers in the front line during a battle.