The Heritage Foundation and two other conservative groups are fighting subpoenas to turn over documents that plaintiffs are seeking as part of their federal lawsuits against President Trump’s transgender military service policy.

Active-duty transgender plaintiffs and rights groups in at least two of the federal suits are attempting to force Heritage, as well as the Family Research Council and the Center for Military Readiness, to share any emails or other correspondence with the White House that might have influenced Trump’s decision to rollback open transgender service in July.

Attorneys for Heritage and the Family Research Council have argued in court that the subpoenas violate their rights to free speech and to petition the government, and could open both groups to public harassment or reprisals. A D.C. district court is reviewing the motions.

“Indeed, for FRC, the threat of harassment is far from hypothetical. Websites already collect cherry-picked quotes regarding FRC’s position on issues like those in this suit,” the attorneys argued in an April 23 filing. “Not only does FRC receive hate mail and criticisms on social media because of these quotes, but an FRC employee has been shot by a man enraged by these websites.”

The Justice Department called it “plainly irrelevant information” in a filing April 23 asking that the federal district court in D.C. not force the groups to comply with the subpoenas.

Elaine Donnelly, president of the Center for Military Readiness, told the Washington Examiner that her group has received three subpoenas and is objecting to what she said is an attempt to intimidate the group.

"It appears that they are trying to prove what amounts to a conspiracy theory. In their minds, President Trump did not announce a change in policy for pro-defense reasons,” Donnelly said in a released statement. “He must have been motivated by personal ‘animus’ against transgenders, not the advice of military leaders. None of this is true.”

The Heritage Foundation, which said it has no comment on the legal dispute, has been influential on Trump’s military policies and has supported his proposal to restrict transgender service. The Family Research Council, which did not return a request for comment, and the Center for Military Readiness have strongly opposed integration of transgender troops.

Jerry Boykin, the executive vice president of the Family Research Council, sent letters to Defense Secretary Jim Mattis and Adm. John Richardson, the chief of naval operations, in the spring of 2017 asking for deeper study of the cost of allowing open transgender service, according to documents produced in court filings.

“We fear that this policy will turn our naval and marine officers into medical case workers expected to deal with extremely complex medical and psychological issues,” Boykin wrote about two months before Mattis decided to delay plans to allow transgender recruiting.

So far, the conservative groups have not turned over any of the subpoenaed documents, which includes contacts with Trump, Vice President Mike Pence, and their executive staff going back to September 2017, according to Shannon Minter, a lead attorney in lawsuits in D.C. and California and the legal director of the National Center for Lesbian Rights.

“We want to understand the process and what drove it, and who had input,” Minter wrote in an email to the Washington Examiner on Monday.

Trump sent tweets in July announcing that he had consulted with military leaders and would no longer allow transgender troops to serve in any capacity. The move rolled back the President Barack Obama administration’s year-old open service policy and took many at the Pentagon and on Capitol Hill by surprise.

The Heritage Foundation and the Family Research Council were both served with subpoenas last month and were ordered to turn over the documents by April 25, according to a federal court filing in D.C.

Plaintiffs suing Trump over the policy argue in the court filing that emails and other communications could provide a window on whether “stereotypes, prejudice, or animus” were motivating factors at the White House leading up to the proposed policy change.

“The communications at issue here may show that, contrary to defendants’ assertions, the transgender ban was in fact heavily influenced by outside groups that oppose civil rights for transgender people and that have advocated for barring transgender people from military service,” according to the court document.

Transgender troops and potential recruits quickly filed four federal lawsuits backed by national transgender rights advocates following Trump’s tweets in July.

The suits have been hammering on the president’s claim that he consulted with “my Generals and military experts” on the transgender policy leading up to his announcement.

Court filings have showed that Gen. Joseph Dunford, the chairman of the Joint Chiefs of Staff, emailed the military chiefs a day later acknowledging Trump’s announcement was “unexpected” and laying out a brief plan for how to deal with it.

“P.S. When asked, I will state that I was not consulted,” Dunford wrote in a follow-up email response a few hours later.

So far, the plaintiffs have won injunctions that are blocking the Pentagon from implementing its new proposed personnel policy, which was written in the months after Trump’s tweets and would bar many transgender people from serving.

The lawsuits are now moving into the discovery phase and possible trials later this year.