BBC NEWS | England | London | Mayor wants 'swift' Green inquiry
Boris Johnson said he anticipated a "swift and proportionate" inquiry into his role in the Damian Green affair.
London's mayor has been accused of prejudging the outcome of a police investigation into Tory MP Mr Green, who was accused of leaking documents.
The Metropolitan Police Authority (MPA) and Greater London Authority (GLA) will report on its investigation on 4 March.
If upheld, it could lead to Mr Johnson being suspended for up to six months or potentially being removed as mayor.
Mr Green was arrested in November as part of an ongoing Scotland Yard probe into the leaking of sensitive Home Office information.
On 3 December the mayor told an MPA meeting he believed Mr Green would be vindicated and admitted discussing the case with him.
London Assembly Labour group leader, Len Duvall, lodged a formal complaint, and said Mr Johnson had brought the mayor's office into "disrepute".
Mr Duvall said Mr Johnson should not have revealed information given to him privately by senior police officers or discussed the case with Mr Green.
On Wednesday a GLA sub-committee confirmed Mr Johnson would be investigated in regard to the matter.
The mayor's spokesman said: "The mayor is pleased that the sub-committee has concluded that there is no need to refer this matter to the Standards Board for England and that they have not concluded that there were any breaches of the code of conduct.
"He welcomes their promise of a swift and 'proportionate' inquiry - hopefully at minimal expense to the London taxpayer."