(CNN) Republicans -- in a last minute decision -- decided to postpone a vote on a comprehensive immigration bill for the second time in less than a day, a sign of the struggles leaders are having to unite the conference on such a contentious topic.

An aide told CNN that the plan is for members to work over the weekend to try to craft a bill that can gain more support next week.

"There's active negotiations," said Rep. Joe Barton, a Republican from Texas. "They are just going to try and take (it) and add a few things to it to get another 20 votes."

According to two people in the room, the decision to postpone the vote came in the final 20 minutes of the conference meeting when many of the members had already left. Majority Whip Steve Scalise and Majority Leader Kevin McCarthy "saw a potential opening" in the discussions, per one person. The decision was made to try to make something happen in the days ahead.

"It was a well-attended conference where it gave our entire conference an opportunity to have a full discussion on these very important issues," said Rep. Jeff Denham, a Republican from California who has worked with lawmakers for weeks on compromise legislation.

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