(AP) – The Missouri Association for Social Welfare is challenging the language of a potential ballot measure on a sales tax increase for transportation projects.

The association filed a lawsuit Monday over the summary that voters would see if supporters gather enough signatures to get the proposed constitutional amendment on the 2014 ballot.

Objections include the summary’s description of the tax increase as “1 percent” instead of one percentage point, and a statement that toll roads would be prohibited. Opponents say the initiative requires voter approval to add tolls on roads or bridges that exist before 2014, which could allow tolls on structures that are built later.

Bill McKenna, co-chairman of a group promoting the measure, says challenges to ballot summaries seldom succeed and will not in this instance.