How to add margin or padding in Flutter BottomNavigationBarItem

I have implemented a BottomNavigationBar. Each BottomNavigationBarItem has icon and label. I want to give margin or padding to each BottomNavigationBarItem separately.

BottomNavigationBarItem(
  icon: Container(
          padding: EdgeInsets.only(
            bottom: 10,
          ),
          margin: EdgeInsets.only(
            left: 20,
          ),
          child: Image.asset(
            "assets/icons/icn_home_selected.png",
            height: 16,
            width: 16,
          ),
        ),
  label: "Home",
)

Wrapping the icon with Container and using margin property I am able to move the icon but how can we move label?