Sen. Rob Portman has his first opportunity to support gay rights legislation on Thursday, when a bipartisan group of senators plans to reintroduce the Employment Non-Discrimination Act.

In March, the Ohio Republican became the first GOP senator to support gay marriage, but Portman said Wednesday that he is still unsure whether he will support the legislative effort to expand federal equal opportunity labor laws to protect gay and lesbian workers.

Portman has talked briefly with Sen. Jeff Merkley, D-Ore., one of the five co-sponsors of the bill, but that conversation was not particularly substantive on either side.

“We haven’t had any extensive discussions yet,” Portman said Wednesday. “I need to look at it.”

Merkley, along with Democrats Tammy Baldwin of Wisconsin and Tom Harkin of Iowa and Republicans Mark S. Kirk of Illinois and Susan Collins of Maine are the original co-sponsors of the bill being introduced.