How exactly do you plan on enforcing this?
Many shop owners in my area refuse to accept 10p and 20p coins. Some even reject 50p coins, claiming that “nobody accepts them anymore.” How do you intend to ensure that these businesses are properly educated and, more importantly, punished if they continue refusing legal tender?
A woman recently refused to sell me something I needed simply because I paid with a 10p coin and two 20p coins, making 50p in total. Her reason was that when she goes to the market, nobody accepts those coins from her.
This is exactly why enforcement is necessary. Commercial drivers also routinely refuse coins. If these coins are legal tender, people should not be allowed to arbitrarily reject them. Educate them first, and if they still refuse to comply, enforce the law.