(JEFFERSON CITY, Mo., AP) — A Missouri House panel that tried to subpoena members of Gov. Jay Nixon’s staff says it now will hear from them voluntarily.

Republican Rep. Stanley Cox says six current members of Nixon’s administration and a former Revenue Department director are to testify Tuesday and Wednesday before a committee he leads.

The panel is looking into a Revenue Department decision last year to start making electronic copies of birth certificates, concealed gun permits and other personal documents of applicants for driver’s licenses and state identification cards. After Nixon’s administration initially defended the policy, the governor signed legislation earlier this month immediately halting it.

Cox says he still wants to hear from Nixon’s staffers to determine who instigated the policy and why.

A judge blocked subpoenas for the staff last month.