David Cameron has conceded he has no control over when the Chilcot report into the Iraq war will appear after previously urging the inquiry to publish before Christmas.

The prime minister was asked when the long-running inquiry would finally return its conclusions on the day a US report found the CIA used ineffective and brutal methods of torture in the aftermath of 9/11.

Cameron has been facing questions about delays and redactions to the Chilcot report as US and UK intelligence agencies come under increasing scrutiny over the methods they use to prevent terrorism.

In May, the prime minister said: “I want to see [the report] published soon. My understanding is that they will be able to publish before the end of the year and I very much hope they can deliver on that timetable. The public wants to see the answers of the inquiry and I think we shouldn’t have to wait too much longer.”

After the CIA report emerged on Tuesday, Cameron was asked again whether Chilcot will be published before the end of the year as the British public needs answers. He said: “On the Chilcot inquiry nothing has changed in terms of my view but I am not in control of when this report is published. It is an independent report, it is very important in our system that these sort of reports are not controlled or timed by the government. They are controlled and timed by the independent inquiry board that has carried out that vital work. And when they publish is a matter for them.”

Cameron’s refusal to express confidence that the inquiry will meet the timetable he requested will fuel speculation that the report will not now be published until after the general election. Whitehall sources have previously conceded this may be the most likely outcome.

Labour would be likely to object strongly if the report is scheduled to emerge during the election campaign period because it is expected to be highly critical of former prime minister Tony Blair.

There have been lengthy delays to the five-year inquiry because of diplomatic negotiations between the US and UK about what can be revealed from correspondence between Blair and former president George Bush.

There have been reports, however, that Blair and others criticised by the inquiry have now received official notifications of what it will say about them and been given the chance to respond.

Blair’s office insists that he has no interest in delaying publication and he would like the report published so he can justify his actions in the face of claims that he misled the public about the reasons for going to war.

On Tuesday, Sir Menzies Campbell, a Liberal Democrat member of the intelligence and security committee, said: “It is thoroughly regrettable, to put it mildly, that this report has not yet been published. Delay is not in the public interest nor that of individuals who may eventually be the subject of criticism. I’m surprised that the prime minister is not more exercised about the delay. But I hope we can infer that no deal has been done between the Conservatives and Labour to time publication so as to avoid any embarrassment for either party before next year’s election.”