Yes but the last time a monarch vetoed a law was in 1707, and that was only because parliament asked Queen Anne to veto the law.
In reality, if King Charles started vetoing then after a short constitutional crisis, parliament would basically just change the rules of the game to say that the monarch no longer has the power to veto laws.
>>alicha+(OP)
Wouldn’t the loophole still be if one house of the parliament co-opts King, essentially simulating American democracy where you have a Republican King and Republican Party in power allowing the Republicans to veto laws and stop monarchy reform in parliament?