Australian Canon Richardson, a former dean of St Paul's Cathedral in Melbourne, said the special Anglican wing the Vatican set up to provide a home for Anglican dissidents would not last more than 20 years.
Canon Richardson, whose term as ambassador for the Archbishop of Canterbury ended on Friday, said the Vatican told Archbishop of Canterbury Rowan Williams only a fortnight before the announcement.
He told ABC Radio's The Religion Report, in an interview that he and Dr Williams were offended by the manner and timing of the intervention.