CHICAGO (WLS) — Two of the unions that helped get Chicago Mayor Brandon Johnson elected are now at odds.

The Service Employees International Union said it’s under attack by the Chicago Teachers Union.

ABC7 Chicago is now streaming 24/7. Click here to watch

There’s concern about the impact that could have on jobs.

The two unions are now at odds over a CTU contract proposal that SEIU said would take thousands of members away from Local 73.

“We would say that it threatens the integrity of our bargaining unit that we’ve represented for over 20 years, and typically that is defined as a raid,” said Stacia Scott Kennedy, executive vice president of SEIU Local 73.

For months, Scott Kennedy said her union has tried to work with CTU on its contract demand with Chicago Public Schools, but unsuccessfully. This week, the SEIU State Local Council passed a resolution, saying it is “under attack” from the CTU.

“It’s pretty unfortunate and disappointing that it’s gotten to the point where SEIU has had to draft a resolution, get it voted on and passed, to actually call this out,” 40th Ward Ald. Andre Vasquez said.

Progressive Alderman Vasquez and others say for the sake of union solidarity in Chicago, the dispute must be worked out.

SEE ALSO: CTU could inch closer to strike after rejecting CPS fact-finder report

“It is extremely unusual for unions to be in a public fight like this and for one union challenge another, especially if they’re politically aligned,” ABC7 Chicago political analyst Laura Washington said.

The conflict is over CPS special education classroom assistants, known as SECAs. SEIU has jurisdiction over 7,200 aides.

“SECAs are there to service students with disabilities, and they are not there to make copies or do bulletin boards or teach or recess or lunch monitoring,” Scott Kennedy said.

Scott Kennedy said the union wants to diminish special education assistants’ roles in helping students with personal hygiene and feeding. CTU’s contract demand calls for teaching assistants to help with the education part of it. CTU originally turned down jurisdiction over SECAs.

“In 1999, the position was created. CPS decided that there was a need for the position. They first went to the Chicago Teachers Union, and the Chicago Teachers Union said they weren’t interested,” Scott Kennedy said.

Scott Kennedy said if CPS agrees to CTU’s contract demand, SEIU Local 73’s membership could possibly dwindle to 500 people.

In a statement, CTU said all they are asking for is before assigning a SECA to every special ed student, CPS should evaluate the needs of the student, on whether a SECA or teacher’s aide is necessary.

CTU said it will continue to collaborate closely with SEIU.