Utah Attorney General Sean Reyes has joined 21 other state attorneys general in sending a letter to Pres. Joe Biden expressing their displeasure with his COVID-19 vaccine mandate for federal contractors. Saying the action “stands on shaky legal ground,” the state officials said specifically that it confuses contractors and will likely exacerbate the nation’s current supply-chain problems.

The attorneys general complained that companies face blacklisting for federal contracts unless they get their workers vaccinated on “an unworkable timeline.”

“We strongly urge you to instruct agencies to cease implementing the mandate or, at a minimum, to provide clarity to agencies and federal contractors across the country and delay the mandate’s compliance date,” said the letter signed by attorneys general from Texas, Mississippi, Alaska and other states in addition to Reyes.

Reyes had already joined Republican officials from across the nation threatening over the order that Biden issued Sept. 9.

Biden is expected to release details soon about implementing the mandate. He has said companies with at least 100 employees will have to require all their employees be vaccinated or undergo weekly testing.  The mandate for federal contractors goes into effect in December, and it does not have an option for regular testing in lieu of vaccination.