Rejection of an invitation to speak at a conference / corporate event due to lack of time to prepare.
Thank you for your invitation to [speak / host / be a panelist] at your [annual meeting / convention / conference / seminar] for [Company / Society] on [date].
I feel that I will not have sufficient time to prepare myself in time for the [annual meeting / convention / conference / seminar].
I will be happy to address your organisation on another occasion if you would give me a bit more notice in advance.
invitation to speak,
lack of time,