NASHVILLE (AP) - A constitutional amendment to ban an income tax in Tennessee has passed the House.

The measure was approved 73-17 on Thursday. The companion legislation passed the Senate last year. The measure must now be approved by a two-thirds vote of both chambers in the next General Assembly before it's placed on the ballot in 2014.

Opponents of the legislation say it's unnecessary because the state constitution already bans an income tax and that the measure is politically motivated.

However, Republican sponsor Glen Casada of Franklin says a judge could decide otherwise concerning the constitutionality of an income tax and that the legislation is needed to "make it clear it is not constitutional."