President Donald Trump plans to sign an executive order Thursday targeting a rarely enforced IRS rule that says religious organizations and other non-profits that endorse political candidates risk losing their tax-exempt status.

The order also promises "regulatory relief" for groups with religious objections to the preventive services requirement in the Affordable Care Act, according to a White House official. Those requirements include covering birth control and the move could apply to religious groups like the Little Sisters of the Poor, who have moral objections to paying for contraception.

Trump will sign the order as he marks the National Day of Prayer at the White House Thursday. He was hosting members of his evangelical advisory board at a dinner Wednesday night and planned to meet Roman Catholic leaders in the Oval Office before signing the order.

The White House did not release the full text of the order and it was not clear just how those pledges would be carried out. The plans fall short of what religious conservatives expected of the president, who won overwhelming support from evangelicals by promising to "protect Christianity" and religious freedom.

Ralph Reed, a longtime evangelical leader and founder of the Faith & Freedom Coalition, said he was briefed by White House officials about the text of the executive order. Reed called the provisions an excellent first step in the Trump administration's plans for protecting religious freedom

Reed said he was "thrilled" by the language on the IRS restrictions on partisan political activity. "This administratively removes the threat of harassment," Reed said in a phone interview. "That is a really big deal." He said the language in the order related to the preventive care mandate will "ensure that as long as Donald Trump is president, that something like the Little Sisters of the Poor case will never happen again."

Still, Mark Silk, a professor at Trinity College in Connecticut who writes extensively on religious freedom, called the planned actions as described by the White House as "very weak tea," especially compared to the draft religious freedom executive order that leaked earlier this year, which had sweeping provisions on conscience protections for faith-based ministries and schools, and federal workers across an array of agencies. "It's gestural as far as I can tell," Silk said. "It seems like a whimper."

Trump has long pledged to protect religious freedom. He promised to "totally destroy" the law prohibiting the political activities, known as the Johnson Amendment, when he spoke in February at the National Prayer Breakfast, a high-profile Washington event with faith leaders, politicians and dignitaries. Fully abolishing the regulation would take an act of Congress, but Trump can direct the IRS not to enforce the prohibitions.

The White House official, who sought anonymity despite the president's criticism of anonymous sources, told reporters Wednesday night that the order will direct the IRS to use "maximum enforcement discretion" over the rule. The move is favored by some of the Christian conservatives who helped fuel his rise to the presidency.

The regulation, named for then-Sen. Lyndon Johnson, was enacted in 1954 and prohibited partisan political activity for churches and other tax-exempt organizations. The policy still allows a wide range of advocacy on political issues, but in the case of houses of worship, bars electioneering and outright political endorsements from the pulpit. The rule has rarely been enforced.

The IRS does not make public its investigations in such cases, but only one church is known to have lost its tax-exempt status as a result of the prohibition. The Church at Pierce Creek in Conklin, New York, was penalized for taking out newspaper ads telling Christians they could not vote for Bill Clinton in the 1992 presidential election. Even so, some religious leaders have argued the rule has a chilling effect on free speech, and have advocated for years for repeal.

While Trump's action on the Johnson Amendment aims to please religious conservatives, some oppose any action that would weaken the policy.

In a February survey of evangelical leaders conducted by the National Association of Evangelicals, which represents churches from about 40 denominations, 89 percent said pastors should not endorse political candidates from the pulpit. Nearly 100 clergy and faith leaders from across a range of denominations sent a letter last month to congressional leaders urging them to uphold the regulation. They said the IRS rule protects houses of worship and religious groups from political pressure.

Easing political activity rules for churches also raises questions about whether churches could be pulled into the campaign finance sphere and effectively become "dark money" committees that play partisan politics without disclosing donors.

The order's health care provision could apply to groups like the Little Sisters of the Poor, who run more than two dozen nursing homes for impoverished seniors, and have moral objections to paying the birth control costs of women in their health plans. The Obama administration created a buffer meant to shield those groups, but they said it didn't go far enough. They continued to press their case in the courts. Last year, the Supreme Court asked lower courts to take another look at the issue in search of a compromise.