After a separate investigation the committee has also called for Lord Stone to be suspended for six months after finding he had bullied parliamentary security staff.
The former Marks and Spencer executive admitted to using an "aggressive" tone when contacted by security staff after leaving his suitcase unattended by an entrance to the parliamentary estate, contrary to the rules.
The report said: "In subsequent exchanges with security officers, on the telephone and in person, Lord Stone raised his voice, gesticulated, spoke over them and described (an officer) as 'thick and stupid'."
He refused to move his suitcase and used rude and offensive language.
Lord Stone appealed against an initial investigation by the Lords' Standards Commissioner that found he had bullied the staff, but the Conduct Committee upheld the findings.
He had previously been found to have sexually harassed staff by the Commissioner in 2019, leading to him losing the Labour whip.
After two allegations against him were upheld, he agreed to take part in a course of "bespoke training and behaviour coaching sessions".
In Thursday's report, the committee said: "The present case demonstrates that the clear pattern of Lord Stone's poor behaviour continues.
"Despite the hope we expressed in 2020, Lord Stone appears to have no greater insight into his behaviour now than he did then.
"His continued inability to control his behaviour and to treat staff with respect and courtesy is unacceptable."
Peers need to approve the sanction before it can be implemented, with a vote to do so expected early in 2025.
