Senior members of Tony Blair's staff are openly discussing a possible successor to Alastair Campbell, Tony Blair's spokesman and closest and longest-serving adviser who is believed to be on the verge of resigning.
Staff are talking about whether Blair will promote someone from inside his office or headhunt someone from political journalism, as he did with Campbell.
Such speculation is potentially destabilizing when the government is at its most vulnerable since taking power six years ago.
Campbell on Friday passed up a chance to deny it outright, saying instead: "I would respectfully suggest it is wishful thinking."
Campbell has discussed with friends, however, what he might do outside the government, according to close colleagues.
Blair's staff say they are increasingly convinced he is considering whether to depart in September when Fiona Millar, his partner and press secretary to Tony Blair's wife Cherie Blair, is expected to leave her job.
"It's pretty clear that, the way his mind is working, he will go," said a well-placed government figure.
"But he wants the summer to make up his mind. It's a big decision, it will be a big wrench," the source said.
A former tabloid newspaper journalist, Campbell, 46, has exercised unprecedented power as a communications chief and was dubbed "the real deputy prime minister" when it emerged his influence extended far beyond media matters.
He was censured by the UK's House of Commons foreign affairs committee over his role in February's so-called dodgy dossier on Iraq's weapons of mass destruction.
He has also picked a very public fight with BBC correspondent Andrew Gilligan, members of parliament deciding the reporter was wrong to accuse Campbell of inserting a 45-minute warning into a September dossier.
Campbell, who retreated into the shadows after the 2001 election when he ceased briefing parliamentary journalists every day, gave evidence to the committee and appeared on TV.
One colleague said if Campbell announced now that he was to go, it would appear that he had lost the battle with the BBC.
"How could he do it now with the BBC row? You would get huge conspiracy theories," argued the government official, who said the reason for both Campbell and Millar wanting to leave was that "you get to a stage where you want to do something else."
Campbell's exit would cost Mr Blair one of his most valuable courtiers.