Opponents of a law that would ban abortion after 18 weeks are planning to sue, after Utah's Governor Gary Herbert signed the bill on Monday. 

The A-C-L-U said in a statement that their challenges to House Bill 136 will argue that pre-viability abortion restrictions are unconstitutional. 

The A-C-L-U and the Planned Parenthood Association of Utah promised a joint suit Monday, but they didn't say when it would be filed. 

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