Updated at 3:37 p.m. Friday to include reaction from Dallas child advocate.

AUSTIN — The state's top protective services official, conceding it's "unacceptable" that tens of thousands of children at risk of abuse and neglect haven't had a timely visit from Child Protective Services, is asking permission to promptly hire 550 new front-line workers.

Texas' top three GOP leaders appear ready to sign off on a sizable and immediate infusion of money and new employees at CPS -- but not the big pay raises some child advocates say are needed to stabilize the agency.

"My expectations are not being met," Henry "Hank" Whitman, head of the Department of Family and Protective Services, said in a letter Thursday to Gov. Greg Abbott, Lt. Gov. Dan Patrick and House Speaker Joe Straus.

"Texas children remain at risk. This is unacceptable," said Whitman, a former lawman whom Abbott's social services czar installed atop the besieged, 12,000-employee department last spring.

He inherited a breakdown in Dallas County CPS investigations and shortages of foster care beds that are forcing scores of children each month to bed down in state offices for two or more nights -- under the watch of already overworked and frazzled caseworkers.

In July, Whitman issued a "10-point plan" for agency improvements. Last month, he submitted a budget request for 2018-2019. If approved by lawmakers next year, it would let CPS hire more than 880 new front-line workers and child-abuse hotline intake specialists.

But on his brief watch, performance by child-abuse investigators in the Houston area continued to slip, despite a report by The Dallas Morning News last spring showing Harris County was headed for trouble, possibly disaster.

Last week, after analyzing an agency database tracking initial visits with kids mentioned in more than 7,300 child-maltreatment cases in the Houston area, The News reported that through early September, half of children referred to Harris County's weren't being seen on time. In 1 of every 5 open cases, children weren't being seen at all.

After the newspaper shared its findings with the governor's office, Abbott and the two top legislative leaders, Patrick and Straus, released a joint letter in which they condemned the agency's failure to check on at-risk children promptly. They called for "action plans" that would "proactively prevent additional lapses in the required face-to-face visitations and interventions."

In his response Thursday, Whitman said CPS "is struggling to meet the timeframes for initial contact and timely case closure" in North Texas, Harris County and the agency's Central Texas region that includes Austin.

"The additional staff will be strategically placed in those areas of the state where need is the highest," he said.

The plan would station 88 percent of the 550 new front-line workers in Dallas-Fort Worth, Harris County and the Austin region.

Reflecting Whitman's background as a former chief of the Texas Rangers, it increases tenfold his original budget ask for 10 more "special investigators," who are former law enforcement officers.

Anticipating there will be more children who need services or must be removed from their birth families, Whitman said the "downstream impact" means CPS doesn't just need more investigative types.

Among the 550 new workers he wants to begin hiring immediately would be 105 "conservatorship caseworkers," who find placements for foster children and report on their status to judges; and 145 more "family based safety services caseworkers," who work with parents to prevent removals.

On Friday, Straus thanked Whitman and CPS leaders for responding to leaders' request for quick improvements.

"Members of the House and I will review this proposal promptly and visit with CPS about its impact so that we can act in the very near future to help these children," Straus, a San Antonio Republican, said in a written statement.

On Wednesday, the budget-writing Senate Finance Committee will review Whitman's requests. Flower Mound GOP Sen. Jane Nelson, the panel's chairwoman, has asked for an update on unexpected expenses in the current budget cycle that will need to be paid for next year in an emergency or "supplemental" spending bill. Including federal funds, Whitman's plan for immediate hires would cost the state about $53 million in the current year, which ends Aug. 31.

Earlier, he asked for $498 million more in state general-purpose revenue spending in the next two-year cycle -- a 26-percent increase.

In Thursday's letter, Whitman also noted top concerns of Abbott and Patrick. In a nod to the governor, who has stressed getting tough with CPS employees, Whitman said he wants to make candidates for supervisor jobs prove they're competent before they are granted job interviews.

In a bow to Patrick, who presides over the Senate and wants more churches involved in recruiting foster parents, he noted there will be a Faith Leader Summit in Austin on Nov. 2. CPS will create a new position, a "Faith-Based Director," to act as liaison to religious communities, Whitman said.

Whitman, though, was silent about a pay raise. Many child advocates and the Texas State Employees Union insist an across-the-board increase in caseworker salaries -- which at CPS can be as low as $34,000 -- is needed to reduce sky-high turnover. Retaining more workers is the key to reducing caseloads and doing a better job for children, they say.

In a "placeholder" in his budget request for the next two-year cycle, Whitman suggested he may ask lawmakers for money to pay more to "high-performing staff." He did not elaborate.

In the last budget year, 57 percent of Dallas County CPS investigators quit. In Tarrant, the turnover rate was 39 percent; Travis, 35 percent; Bexar, 31 percent; and Harris, 30 percent.

As of August, there were 389 unfilled CPS caseworker jobs statewide. Of those, 200 were investigator posts -- 32 in Dallas County and 18 in Tarrant.

On Friday, Dallas child advocate Madeline McClure praised the agency leadership for recognizing it needs a bigger workforce of front-line workers. But she said Whitman's plan "is missing a key component -- competitive salaries at a level that will actually fill the positions and keep them filled with qualified caseworkers."

McClure, chief executive of TexProtects, the Texas Association for the Protection of Children, noted that CPS' turnover rate is nearly double that at other state agencies.

"Remember, we already have about 400 vacancies in high-need areas," she said in a written statement. "We may hire 550 additional workers, but who will we retain who can handle the pressure and rigor of this job at a $34,000 entry-level salary?"

Staff writer J. David McSwane contributed to this report.