White House press secretary Sarah Sanders speaks with reporters in the driveway at the White House on Wednesday. The White House has imposed new rules on issuing credentials for journalists. (Jonathan Ernst/Reuters)

The White House has implemented new rules that it says will cut down on the number of journalists who hold “hard” passes, the credentials that allow reporters and technicians to enter the grounds without seeking daily permission.

The new policy has been met with some confusion and even worry among journalists, some of whom suspect that the ultimate aim is to keep critics in the press away from the White House and President Trump.

White House press secretary Sarah Sanders explicitly denied that, saying the changes were prompted by security concerns, not to punish journalists. “No one’s access is being limited,” she said Wednesday night.

Under procedures announced in March and implemented over the past few weeks, journalists will qualify to renew their hard passes only if they have entered the White House grounds at least 50 percent of the time in the 180 days before renewal, effectively once every other day. If they fall short of this, their hard passes will not be renewed.

A nonrenewal doesn’t preclude journalists from entering the White House entirely, but it does subject them to a more cumbersome process. Without a hard pass, they must apply each time they want access on a daily, weekly or six-month basis. Hard passes are valid for two years.

Sanders said the new measures were prompted by the U.S. Secret Service’s concern about the proliferation of hard passes, particularly over the past three years. It’s unclear exactly how many journalists hold hard passes, but White House officials say there could be as many as a thousand in existence.

Some of the confusion about the new policy seems to be a result of the White House’s policy of making exceptions to the 50 percent rule.

In its March notice, the White House said it will exempt “senior journalists” who don’t meet the new standard but who are “nonetheless consistently engaged in covering the White House.” It also said the press secretary could grant exemptions for “special circumstances,” such as maternity leave.

The White House hasn’t spelled out how it will make these decisions, raising concerns about arbitrary or selective decisions. (The Washington Post’s seven White House reporters have all been granted exemptions).

The White House last year revoked the hard pass of CNN reporter Jim Acosta after Acosta engaged in a heated exchange with Trump during a White House news briefing. After a brief legal fight, a federal court ordered the White House to restore Acosta’s access. The court said Acosta’s due-process rights had been violated because the White House had never established rules and procedures for revoking a credential.

But Sanders said the new policy was unrelated to Acosta’s case. Acosta continues to hold a hard pass.

In an opinion piece published Wednesday, Post columnist Dana Milbank wrote that he was denied a hard pass, although the paper’s reporters who cover the White House were all granted exemptions. “The White House press office granted exceptions to the [others], but not to me,” he wrote. “I strongly suspect it’s because I’m a Trump critic. The move is perfectly in line with Trump’s banning of certain news organizations, including The Post, from his campaign events, and his threats to revoke White House credentials of journalists he doesn’t like.”

The White House Correspondents’ Association, which represents journalists on access issues, was consulted about the new policy, according to Sanders. The organization’s president, Olivier Knox, declined to comment.

It’s also not clear whether the White House is accurately counting the number of days that reporters enter the grounds. One journalist said she received an email notifying her that she had met the standard and that she had been granted renewal of her hard pass — despite the fact that she has been to the White House only a few times over the past year.

In any case, the 50 percent rule has become increasingly impractical for many reporters because of other press restrictions imposed by the White House. Sanders, for example, has held only two formal news briefings since the start of the year, including a record stretch of 59 days without a briefing as of Thursday.

Trump and Sanders continue to hold unscheduled “gaggles” on the White House grounds, but the disappearance of the briefing has led many reporters to work away from the White House.

Reporters from accredited news organizations submit an application for a hard pass along with a letter from a senior editor vouching for them.