David Cameron said he expected the long-awaited Chilcot report into the Iraq War to be published by the end of the year.
The Prime Minister said it was "frustrating" that publication had been delayed and that the public "wants to see the answers of the inquiry".
Sir John Chilcot's inquiry completed public hearings in 2011, but the release of its report is understood to have been held back by negotiations over the publication of private communications between Tony Blair, prime minister at the time of the 2003 conflict, and then-US president George Bush.
The House of Commons Public Administration Committee described the delay as very serious and its chairman, Bernard Jenkin, has written to the Cabinet Office demanding an explanation for the hold-up.
Mr Cameron told Sky News: "My understanding is they will be able to publish before the end of the year and I much hope they can deliver on that timetable.
"The public wants to see the answers of the inquiry and we shouldn't have to wait too much longer."
The report could prove difficult for Labour in the build-up to the 2015 general election, reviving the issue of Mr Blair's decision to take the country to war.
Mr Jenkin said he is ready to summon ministers, for questioning by his committee on the reason why the report has not yet been published.
In an interview for BBC2's Daily Politics, Mr Jenkin said: "It's very serious this report is at least four years overdue, so we've written to the minister to ask for an explanation as to why these delays have occurred, what is holding up the publication of the report and how these issues are going to be resolved."
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article