Ken Livingstone is likely to apologise for comparing a Jewish journalist for the Evening Standard to a concentration camp guard, his deputy has said.
Ken Livingstone has refused to apologise for the remarks
Nicky Gavron told the BBC's Politics Show she believed the Mayor of London would say sorry on Tuesday for offending the wider Jewish community.
The Prime Minister Tony Blair is among those who have called for an apology but so far the mayor has refused.
The exchange happened outside a party for MP Chris Smith over a week ago.
The mayor accused Oliver Finegold of "doorstepping" him at a "predominately gay event".
Ms Gavron said she thought Mr Livingstone's comments were "inappropriate" but she did not believe the mayor was anti-Semitic.
She said: "I work very closely with Ken so I can speak of what he's like in his guarded and unguarded moments and... he is in no way anti-Jewish, I wouldn't for a moment work with him if he were.
"On the other hand, I think his remarks were inappropriate and I believe it is important, and I believe he will, come to the point where he says, 'I regret that I have caused offence to the wider Jewish community'.
"I hope he will do it soon and it is mooted that he is going to make some sort of statement on Tuesday."
Power to suspend
Last week Tory MP Boris Johnson said the mayor should not say sorry.
Mr Johnson was forced to apologise last year for an article in the magazine he edits about Liverpudlians grieving over the death of British hostage Ken Bigley.
The local government watchdog The Standards Board has already received one complaint about the comment from the Board of Deputies of British Jews.
It has the power to suspend or bar the mayor from office.