WASHINGTON, April 23 (Reuters) -

U.S. Supreme Court justices on Tuesday signaled support for

Starbucks ( SBUX ) in the coffee chain's challenge to a judicial

order requiring it to rehire seven employees at a Memphis cafe

who were fired as they pursued unionization.

The justices heard arguments in the Seattle-based company's

appeal of a lower court's approval of an injunction sought by

the U.S. National Labor Relations Board (NLRB) ordering

reinstatement of the workers. The case could make it harder to

quickly halt labor practices challenged as unfair under federal

law while the NLRB resolves complaints.

The dispute centers on the legal standard that federal

courts must use to issue a preliminary injunction requested by

the NLRB under a federal law called the National Labor Relations

Act. Such orders are intended as an interim tool to halt unfair

labor practices while a case proceeds before the board.

Under that law's section 10(j), a court may grant an

injunction if it is deemed "just and proper."

Starbucks ( SBUX ) has argued that the judge who granted the

injunction should have used a stringent four-factor test to

weigh the bid for an injunction, as courts typically do in

non-labor disputes. This test includes an assessment of whether

the side seeking relief would suffer irreparable harm and is

likely to succeed on the merits of the case.

Some justices appeared to agree that courts, not the NLRB,

should have the primary role in determining the likelihood of

success in a case before issuing an injunction.

Conservative Justice Neil Gorsuch told Justice Department

lawyer Austin Raynor, who was defending the Starbucks ( SBUX )

injunction, that other federal agencies are subject to the

stricter standard.

"In all sorts of alphabet soup agencies, we don't do this,"

Gorsuch said, using a term describing agencies known by their

initials. "District courts apply the 'likelihood of success'

test as we normally conceive it. So why is this particular

statutory regime different than so many others?"

Liberal Justice Elena Kagan pressed Raynor to explain "why

courts should apply a lower standard."

Raynor said the reason is "structural" because in unfair

labor disputes, Congress intended through the National Labor

Relations Act for the NLRB to be the primary adjudicator, not

the courts.

"But it also gave this power over injunctions to the court,"

Kagan replied.

Starbucks ( SBUX ) contends that if the lower courts had applied

stricter criteria, this case would have come out differently.

About 400 Starbucks ( SBUX ) locations in the United States have

unionized, involving more than 10,000 employees. Both sides at

times have accused the other of unlawful or improper conduct.

Hundreds of complaints have been filed with the NLRB

accusing Starbucks ( SBUX ) of unlawful labor practices such as firing

union supporters, spying on workers and closing stores during

labor campaigns. Denying wrongdoing, Starbucks ( SBUX ) has said it

respects the right of workers to choose whether to unionize.

In a break from the acrimony, both sides in February agreed

to create a "framework" to guide organizing and collective

bargaining and potentially settle scores of pending legal

disputes.

'CREAM OF THE CROP'

Raynor told the justices that the NLRB seeks 10(j)

injunctions in very few "cream of the crop" cases, last year

requesting just seven even though it receives 20,000 unfair

labor charges annually.

"This is an expert agency that has said, 'We think these are

the most deserving of relief,'" Raynor added.

But conservative Chief Justice John Roberts said that "I

don't know why the inference isn't the exact opposite." Roberts

said these could be the cases that the board feels "are the most

vulnerable."

Conservative Justice Amy Coney Barrett emphasized to Raynor

that federal courts serve as "an independent check" on the

NLRB's power.

"We acknowledge this isn't a rubber stamp," Raynor replied.

Liberal Justice Ketanji Brown Jackson also noted the

relatively small number of injunctions the NLRB seeks annually.

"This is not sounding like a huge problem," Jackson said.

"Whether or not it's a huge problem, what petitioner

(Starbucks ( SBUX )) wants is just a level playing field," Blatt

responded.

The case began in 2022, when the workers at the Memphis

Poplar Avenue store became among the first to unionize. They let

a television news crew into the Starbucks ( SBUX ) cafe after hours to

talk about the union campaign. Seven workers present that

evening were fired, including some belonging to the union

organizing committee.

Employees there eventually voted to join the Workers United

union.

The union filed NLRB unfair labor charges over the firings

and other discipline by managers. The agency sought an

injunction, alleging Starbucks ( SBUX ) unlawfully fired the workers for

supporting unionization and to send a message to other workers.

U.S. District Judge Sheryl Lipman granted the injunction in

2022. The Cincinnati-based 6th U.S. Circuit Court of Appeals

upheld it in 2023.

The Supreme Court's ruling is expected by the end of June.