The effort to order a recount of Wisconsin’s presidential ballots is headed to court.

Green Party candidate Jill Stein’s campaign on Monday filed a lawsuit challenging a decision by state election officials not to order a hand recount of Wisconsin’s presidential ballots. Wisconsin Elections Commission staff said only a court order can prevent clerks from using machines to check vote totals.

The move follows a decision by the Wisconsin Elections Commission earlier in the day to reject Stein’s request for one when she filed her recount petition last week. WEC staff say state law does not allow them to order a hand recount, unless instructed to by a judge, and that the decision on whether to count ballots by hand or to use a machine is up to local clerks.

Stein and independent candidate Rocky De La Fuente argue the recount is needed to ensure hackers did not abuse Wisconsin’s use of electronic voting machines to change the result of the election and to ensure every vote was counted properly. State election officials have defended the procedures used by clerks around the state, and maintain a recount is not likely to change Republican president-elect Donald Trump’s victory in the state. Trump defeated Democrat Hillary Clinton by about 22,000 votes.

A court battle could prove problematic for the already tight deadline for the state to complete a recount and certify the results of the presidential voting. The WEC has ordered clerks to complete their recount by 8 p.m. on December 12, which is just a day before a federal deadline. Currently, the recount in all 72 counties is expected to begin on Thursday.