CHICAGO (AP) — Gov. Pat Quinn says Republican challenger Bruce Rauner should release full tax returns for 2013 and previous years soon to reveal potential conflicts of interest or tax loopholes.

The Chicago Democrat and supporters have focused on the issue recently. Quinn says releasing the documents would clear up questions and says previous GOP nominees for governor have done so.

Rauner has released three years of returns. Rauner spokesman Mike Schrimpf said Tuesday that the Winnetka businessman has filed for an extension of the April 15 filing deadline for 2013 and will make his returns public before the Nov. 4 election.

Schrimpf says Quinn’s comments are “nothing but a political stunt” and that Rauner pro-actively released previous returns.

The candidates are locked in one of the most competitive governor’s races nationwide.

(Copyright 2014 The Associated Press. All rights reserved.)