Officials organizing the Republican convention in Cleveland have a message for GOP staffers who have spoken out against presumptive presidential nominee Donald Trump: look elsewhere if you want to volunteer in July.

According to an email sent to the Republican National Committee’s Professional Volunteer list—a group of party operatives experienced in everything from logistics to communications—those who are not or may not be perceived to be impartial could be disqualified from participating in the convention. The note adds that the guidance was set “due to circumstances this year.” The letter says:

A reminder that the roles we are offering are with the RNC’s Committee on Arrangements. It is Chairman [Reince] Priebus’ expectation that we are all Republicans working toward the greater good of the party, and that we are acting toward that end. If you are a vocal supporter of any particular candidate, or have been vocally in opposition of any candidate, you are welcome to join us in Cleveland, but we may need to consider whether it is appropriate to have you in a role that is expected to be impartial to the candidates seeking the nomination. Thus, if there is any reason you are aware you may not be, or may not be perceived as being impartial, we should discuss whether you should be included in the RNC’s Professional Volunteer program.

One Republican operative who received the email said the guidance wasn’t sent in 2012. “Everyone from [RNC chairman] Reince Priebus to dog catcher has criticized Donald Trump,” said the operative. “Are they going to disqualify Paul Ryan now too?” (Ryan decided to withhold his endorsement of Trump on Thursday.)

Convention spokesperson Kirsten Kukowski said the guidance was reflective of the party’s efforts to unify behind the nominee. “The convention has been working for over a year on preparations for July,” she said. “This is all done knowing there will be a presumptive nominee we will partner with as our Party comes to Cleveland to nominate our candidate to run against the Democrats in the general election. We welcome any volunteers who want to join us in that mission.”

Kukowski would not discuss what level of criticism would disqualify potential volunteers.

Get our Politics Newsletter. The headlines out of Washington never seem to slow. Subscribe to The D.C. Brief to make sense of what matters most. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Contact us at letters@time.com.