WASHINGTON — Frustrated over increasing issues with military salaries, a pair of senators on Wednesday will introduce new legislation to ensure “equal compensation” among senior enlisted servicemembers and limit the president’s ability to reduce troops’ pay raises.

The bill — sponsored by Sens. Joni Ernst, R-Iowa, and Elizabeth Warren, D-Mass. — could affect President Donald Trump’s plans for the 2018 military pay raise, if lawmakers finalize the measure before the end of August.

But it faces an uncertain future, given the busy budget schedule facing Congress in coming weeks and the restrictions it would place on the executive branch.

Under the measure, the president would no longer be able to use “economic concerns” as a reason to decouple the military pay raise from the Employment Cost Index, which estimates private sector wage growth.

Both Trump and President Barack Obama used that clause in recent years to offer smaller-than-expected pay raises for troops, redirecting the money to other readiness and modernization accounts. The bill sponsors criticized that as bad policy.

"Our men and women in uniform‎ serve this country with honor,” said Warren in a statement.  “They know they won't get rich in the military, but they serve with skill and dedication, and they are entitled to basic pay increases that will give them a chance to build some economic security.”

Trump’s suggested pay increase for 2018 is 2.1 percent, equal to the 2018 pay raise but 0.3 percent below the Employment Cost Index figure.

The 2.1 percent pay raise translates into about a $600 annual boost from 2017 pay for younger enlisted ranks, and about $950 a year for more senior enlisted and junior officers. A mid-career officer will see roughly $1,700 a year extra under that plan.

The 0.3 percent difference translates into about $85 lost a year for the junior enlisted, $130 for the senior enlisted and junior officers, and $240 for mid-career officers.

Under the measure, the president would still be able to lower or deny a military pay raise due to “a national emergency.”

The legislation would also mandate the Secretary of Defense carry out a study on senior enlisted pay, and offer a sense of Congress that senior enlisted advisors to the commanders of the combatant commands should get a pay boost.

Currently, most senior enlisted personnel do not receive pay increases based on new responsibilities and assignments. Ernst and Warren said that creates upsetting discrepancies in pay among key advisers.

“Senior enlisted servicemembers carry a great responsibility leading our men and women on and off the battlefield, and we must ensure they receive appropriate compensation as we seek to retain them and strengthen our military,” said Ernst, who served with the Iowa National Guard in the Middle East during the Iraq War.

Military leaders in recent years have discussed building more flexibility into the military pay scale, which is currently based almost entirely on rank and time in service. But those types of suggestions have been met with mixed response from lawmakers and outside advocates.

If it does not advance as a stand-alone measure, the Ernst/Warren bill could be included in the annual defense authorization debate later this summer.