The BBC's guidelines on impartiality explained - and do they apply to Gary Lineker?
Match of the Day presenter Gary Lineker has been told to step back from his role on the BBC show due to views he has expressed on Twitter.
Lineker has more than eight million followers on the social media platform and, after using it to criticise the government's new bill on the treatment of asylum seekers, the BBC has been under pressure to act.
What are the BBC guidelines?
The broadcaster says it is "committed" to achieving due impartiality in all output.
This is "fundamental to our reputation, our values and the trust of audiences", it adds.
Impartiality must be "adequate and appropriate to the output, taking account of the subject and nature of the content, the likely audience expectation and any signposting that may influence that expectation".
It must also "scrutinise arguments, question consensus and hold power to account", the guidelines say.
What about the policy on social media use?
The BBC guidelines acknowledge that social media is "now a part of everyday life".
Staff are allowed to "engage in social media activities if they wish".
But there must be a "clear distinction" between BBC accounts run by the BBC for BBC purposes and personal accounts run by employees for personal purposes, the guidelines say.
A history of Gary Lineker's most controversial tweets
Where does that leave Lineker?
Lineker is a freelance broadcaster at the BBC - not a permanent member of staff.
He does not present news or political content.
He tweeted to the 8.7 million followers of his personal account, which does not include any link to the BBC or Match of the Day in his bio.
But BBC guidelines state: "There are also others who are not journalists or involved in factual programming who nevertheless have an additional responsibility to the BBC because of their profile on the BBC. We expect these individuals to avoid taking sides on party political issues or political controversies and to take care when addressing public policy matters."
And that people who are "clearly identified with the BBC" should behave "in ways that are consistent with the BBC's editorial values and policies".
Richard Sambrook, former director of news at the BBC and director of BBC Global News and the BBC World Service, told the PA news agency: "For a sports presenter in their personal life to express views that aren't impartial, is not as serious as if it was a news journalist."
The BBC has said Lineker will step back from presenting duties on Match of the Day until they have "an agreed and clear position on his use of social media".