Just as all eligible units (i.e. those in base contact with the enemy) must fight in close combat, similarly all models in base contact with an enemy must fight. Models cannot elect not to strike, nor can they normally be prevented from doing so.
Source: Warhammer Armies Project
Just as all eligible units (i.e. those in base contact with the enemy) must fight in close combat, similarly all models in base contact with an enemy must fight. Models cannot elect not to strike, nor can they normally be prevented from doing so.