Crucial staffing and financial decisions regarding the handover from the Healthcare Commission to the Care Quality Commission are still unresolved just two months before the new body takes over.
The Healthcare Commission has identified work around its closure as a "red risk" - the most severe alert - because a number of projects are "not yet defined, resourced or initiated", papers from a commissioners' meeting last week reveal.
The most serious concerns include preparation of the final accounts, information and records management and the decommissioning of estates.
The commission is due to release 15 separate reports between now and 31 March, when it will be absorbed by the CQC.
Delivering this work while winding down the organisation will be "challenging", says a report signed off at the meeting.
In addition, documents say the Healthcare Commission is having to "respond to CQC announcements very quickly and often with very little opportunity to [have] input into the messages". They say a "constantly changing CQC transition programme communications team…continues to prove difficult".
Healthcare Commission chief executive Anna Walker admitted she only discovered the handover would lead to around 400 redundancies after reading last week's HSJ.
She told commissioners at the meeting: "That has not been communicated to us as an executive team."
The papers reveal the commission has handed the Department of Health a "worst case scenario" redundancy bill of£6.1m, in addition to£330,000 in payments in lieu of notice due to 70 staff.
Commissioners also raised concerns over the new complaints system. Complaints will be handled by trusts and, if complainants are still unhappy, the parliamentary and health service ombudsman.
Currently the Healthcare Commission reviews complaints after they are handled by trusts, and in some cases they are escalated to the ombudsman.
But commissioner John Scampion said the new system "implicitly won't work".
He said: "It's an inept way of doing it and I think we should be saying so and not having anything to do with it. I feel very strongly about this aspect… It's selling the Healthcare Commission short."
Head of complaints Susan Achmatowicz said: "I'm concerned about how the changes will be tackled by the local bodies. The DH is running workshops around local complaints resolution. One could argue it's a bit late in the day but sometimes the deadline focuses the mind."
A CQC spokeswoman said redundancies had been discussed many times with the commission. She said the CQC was committed to ensuring a full programme of internal communications continues.