It really depends on what you have. Many litigants believe the other side is lying to the Judge -- that is common. If you can show an outright lie on a material issue you should bring it to the Judge's attention and ask for costs. You can also file a grievance with the Disciplinary Committee. However, I find that most of these situations are not what the litigant thinks.
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A false statement under oath of a material facts is perjury, and is a very serious charge. But it must be a material fact. If he said, for example, that you got coffee from Starbucks when it really was dunkin donuts, that's not material in most cases, unless the issue is where you were at a particular time, etc. but, as Mr. Rothstein points out, clients usually accuse the other side of lying,and in the overwhelming majority of cases, the statements are either simply someone else's perspective of things, or not material. Be guided by your lawyer here.
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