On the eve of a key vote, 40 principals in the East Baton Rouge Parish school system said they have “grave concerns” about a bill aimed at revamping the school district by giving principals new authority.

In a letter to Louisiana House members, the school leaders said the legislation “actually impedes our ability to meet the increasing needs of our challenging, transient, high poverty student population.”

The proposal, Senate Bill 636, has already passed the Senate.

It is scheduled to be voted on in the House on Wednesday.

“Principals do know what’s best and it is not this bill?” the letter says.

Backers of the legislation, including the Baton Rouge Area Chamber, say the changes would make the school district more efficient and improve student achievement.

Follow Will Sentell on Twitter @WillSentell. For more coverage of Louisiana government and politics, follow our Politics blog at http://blogs.theadvocate.com/politicsblog/