A hospital or health care provider, or an employee of a hospital or health care provider, or a supplier, reasonably alleged to be a joint tortfeasor in a cause of action subject to a health care arbitration agreement shall be a necessary party to arbitration binding any of his joint tortfeasors. On application of any party to the arbitration proceeding, the circuit court may stay an arbitration proceeding commenced or threatened on the grounds that a necessary party is not a signatory or party to the agreement. That issue shall be forthwith and summarily tried and a stay ordered if found for the moving party. If found for the opposing party, the court shall order the parties to proceed to arbitration.