Ealing was rated 'weak' by the commission's comprehensive performance assessment last December by default because it had a 'no star' rating for its social services, although other services were rated fair or above.
The council went on to win a legal challenge against the decision in February. But the commission is appealing against the ruling, claiming that it is legally flawed.
'We applied the rules and (the original) rating should stand,' said an Audit Commission spokeswoman.
Morris joins the West London authority on 27 June, when he will be responsible for communicating the council's legal battle externally and internally.
He will lead a team of 18.
Ealing has also hired Luton Council chief executive Darra Singh. He replaces Ealing chief executive Gillian Guy, who has led the authority for ten years.
Ealing said the double recruitment from Luton was a coincidence.
Morris takes over from interim marketing director Richard Davies who left last month.