The UK's four children's commissioners - people chosen specifically to support kids' rights - have called for smacking to be completely banned.
The commissioners for England, Northern Ireland, Scotland and Wales said kids in the UK should be given the same protection as adults from assault.
Light smacking is still legal in the UK as long as it does not leave a mark.
The government has responded by saying parents should still be able to decide how they discipline their children.
Many countries across Europe have already bought in a complete ban on smacking.
Scotland's Commissioner Kathleen Marshall said: "this isn't an issue that's going to go away."