The BBC's news coverage of religion, immigration and Europe is to be scrutinised in an independent review following accusations of liberal bias.
Lord Patten, the BBC Trust chairman, said the review was an acknowledgment of "real and interesting" concerns from some quarters about the impartiality of the BBC's news coverage.
The corporation has long faced accusations of liberal and leftwing bias from politicians and other sections of the media.
The BBC's coverage of controversial topics including immigration, religion and the European Union will come under the spotlight in the review, which is expected to be published in early 2013. It may also include coverage of Islamophobia.
It is the fifth impartiality review by the BBC Trust, the corporation's governing body, and follows an internal 2007 report that described a "largely unconscious self-censorship" that led to certain opinions being routinely under-represented.
Patten said the review would focus on immigration, religion and Europe because those are the topics that provoke most concern from the BBC's critics. He told a Broadcasting Press Guild lunch on Wednesday: "The subjects we thought we would cover, because they are subjects we have had criticism from time to time about breadth of voice issues, are Europe, immigration and religion.
"It's an acceptance that these are areas where people are particularly concerned that we should get it right. We've been criticised in those areas and we think it's very important to listen to that criticism, not necessarily because it's right but because it reflects real and interesting concerns."
The independent report will compare the way the BBC deals with immigration and religion now with coverage in 2007, when the BBC Trust published a 12-point plan in an attempt to silence its critics on impartiality.
The review will examine whether the BBC has improved the impartiality of its news coverage since that report, called From Seesaw to Wagon Wheel. The 2007 report found no evidence of a conscious bias at the corporation, but said senior BBC figures acknowledged a tendency to "groupthink" which often led to an unconscious liberal slant on big issues.
Rightwing sections of the media routinely lambast the corporation over its alleged liberal bias. A Daily Mail leader column last week accused the BBC of double standards, claiming it "consistently attacks Christianity (though never Islam)" and suggested the corporation would have pursued Jimmy Savile "remorselessly" if he was a Catholic priest and not a former BBC presenter.
Presenter Andrew Marr admitted in 2003 that the BBC held liberal preoccupations, but claimed the rest of the media was similarly guilty of bias. Mark Thompson, who stepped down as BBC director general in August, told the New Statesman in 2010 that the BBC had a "massive bias to the left" when he joined 30 years ago.
The inquiry will be led by Stuart Prebble, the former ITV chief executive and World in Action editor. He will examine whether the BBC gives due weight to a range of opinions on sensitive topics and whether editorial decisions to omit certain perspectives have been carefully reached.
Prebble will investigate whether the opinions of viewers and listeners who participate through phone-ins are given appropriate significance. The review will look at whether the BBC has ensured that those who hold minority views are aware they can take part in on-air debates.
David Liddiment, the lead BBC trustee for the review, said the BBC's reputation and commitment to impartiality was in its DNA. He added: "This review will help to ensure it continues to meet audience expectations in this area, looking at how the BBC builds an understanding of breadth of opinion into its approach to its journalism. Part of the review will look at coverage of immigration, religion and the EU – not because we are anticipating a problem there, but because they are subjects on which there are obviously a range of opinions and which will make a valuable contribution to the review."
The BBC Trust has previously examined the impartiality of the corporation's coverage of business, the UK nations, science and the Arab spring.
In 2009, the BBC came under fire for two reports by the Middle East editor Jeremy Bowen on the Arab-Israeli conflict. The corporation's editorial standards committee found that Bowen had breached guidelines on impartiality when he referred to "Zionism's innate instinct to push out the frontier". A report published by the BBC Trust earlier this year described the broadcaster's coverage of the Arab spring as "generally impartial".