Topeka ? The state Senate has refused to move up the effective date of a new law requiring proof of citizenship from people registering to vote in Kansas for the first time.

Legislators approved the requirement earlier this year, specifying that it takes effect in January 2013. Secretary of State Kris Kobach wanted that changed to January 2012.

The Senate turned down Kobach’s proposal Wednesday on a 23-15 vote.

Kobach was behind the proof-of-citizenship law, which he says will fight combat election fraud. Some senators argued for enacting it in time for the 2012 elections, but others resented an attempt to change the law before it takes effect.