The much-delayed report into the Iraq war will be published in June or July 2016, the inquiry's chairman has revealed.
Sir John Chilcot posted a letter to David Cameron on the Iraq Inquiry's website detailing the publication timeline for the two million word report.
The Prime Minister has told Sir John he is "disappointed" with the timetable and urged him to "expedite" the final stages, a letter released by No 10 has revealed.
Sir John has come under fire for delays in producing his report.
When then-Prime Minister Gordon Brown commissioned the inquiry, he said it would take "at least a year".
The inquiry heard 130 sessions of witness evidence and received more than 150,000 documents.
The report's publication has been delayed by a process called "Maxwellisation", under which those who may face criticism - believed to include former prime minister Tony Blair - are given the opportunity to respond before publication.
In a letter to the Prime Minister published on Thursday, Sir John said the text of the report should be completed by April 2016.
The report will then undergo National Security checks to make sure there are no breaches.
Sir John wrote: "We will complete that work as swiftly as possible. I consider that once National Security checking has been completed it should be possible to agree with you a date for publication in June or July 2016.
"Between today and the week of 18 April my colleagues and I will be finalising our findings, including in light of responses to the Maxwellisation process, and to bring that process to its final conclusion."
Responding to Sir John, Mr Cameron said the families of those who served in Iraq would share his disappointment at the timescale.
He wrote: "I recognise that you have a significant task, but would welcome any further steps you can take to expedite the final stages of the inquiry."
