MADISON, Wis. (AP) -- Three congressional Democrats have sent Gov. Scott Walker a letter asking him about testimony he made under oath last year in light of a video that shows Walker talking about using a "divide and conquer" strategy.

Walker answered "no" when asked during the April 2011 House committee hearing if he had a conversation about his proposal effectively ending collective bargaining for most public workers being used to punish members of the opposition party and their donors.

The Democrats ask Walker in the letter to confirm his participation in the conversation caught on the video where he tells a Beloit billionaire he planned to use a "divide and conquer" strategy against the unions.

Walker spokesman Chris Schrimpf did not say in a statement whether Walker would respond to the request.