North Carolina legislators aren't required to give up emails with other lawmakers and staff to those suing over the state's election-overhaul law, but correspondence with third parties is largely fair game, a federal judge ruled Thursday.

U.S. Magistrate Judge Joi Peake ruled on the extent of legislative confidentiality in three lawsuits filed against the state and officials including Gov. Pat McCrory and challenging provisions of the 2013 law. Attorneys are collecting evidence for trial on the lawsuits next summer.

Those who sued demanded emails and other correspondence from more than a dozen state legislators that they hoped would provide insight to why the law was approved. The lawsuits, filed by civil rights groups, the U.S. government and voters among others, say that elements of the law are unconstitutional and discriminatory under the Voting Rights Act because they harm minority voters.

The lawsuits seek to overturn provisions that reduced the number of early voting days by one week, ended same-day registration during the early-voting period and mandate photo identification to vote in 2016.

In her ruling, Peake said legislative privilege applies to communications between legislators and their aides but not between lawmakers and constituents or interest groups. The state's attorneys cited no authority by which lawmakers should receive the privilege simply because they expected privacy with the communications, she wrote.

Peake rejected a request by the suing groups to require state attorneys to create a log of specific documents with lawmakers or staff corresponding with each other and that lawmakers believe are subject to the privilege — presumably for Peake later to decide whether the documents should be disclosed.

The privilege log "would itself significantly intrude into the legislative sphere, and would also place a heavy burden on the legislators in contravention of one of the aims of the legislative privilege," she wrote.