Question

"We must realy issue a proclamation that birds are not to be allowed to die here" says the mayor. Explain. From the happy prince

Answer 1

The above words which is said by the mayor gives a humorous relief to the story since the death of the swallow and the Happy Prince was very heartbreaking. The mayor was disgusted to see a dead bird on the pedestal of the now ugly looking Happy Prince and he didn't want anymore birds to die there. Therefore he wanted to make a proclamation (probably put a sign board) that no birds are allowed to die here. This also shows the stupidity of the mayor.

I just wrote this answer based on my knowledge in the story. I am not sure if this is the correct answer.