We learned a couple of days ago that the UK government had noted that the amendment of the IPCC's procedures, which appeared to prevent reviewers seeing the other review comments, had been made in error.

The text deleted was this:

All written expert, and government review comments will be made available to reviewers on request during the review process

Now, Marcel Crok is able to confirm that this deletion will indeed by reversed, pointing to this document, which proposes a reversion to the original text be made at the next IPCC meeting at the start of June.

...the deletion of the first part of the original sentence was erroneous. The IPCC-33 decision only pertained to the open availability of drafts, comments and responses, and not to the availability to reviewers on request. Hence, the erroneous deletion of the “All written . . . review process” should be corrected.

In an email, David Holland notes that it remains unclear as to whether the reviewers will be able to see the lead authors' responses.