British Prime Minister Boris Johnson says people should not be prohibited from singing Swing Low, Sweet Chariot at England rugby matches.

The Rugby Football Union said on Thursday it was reviewing the historical context of a song which has been a Twickenham staple for years.

With the ongoing focus on the Black Lives Matters protests, the RFU has decided many who enjoy the song do not know its story and stands ready to address the issue. It is believed to have its roots in American slavery, with its credited author being Wallace Willis - a freed slave from 19th century Oklahoma.

The PM was asked about the issue on Friday, and said: "I certainly don't think there should be any prohibition on singing that song."

He said people from ethnic minority backgrounds should not face "unfairness" in any area of life, but that there should be less focus on "the symbols of discrimination".

Former England international Brian Moore says he "hates" Swing Low, Sweet Chariot as the Rugby Football Union reviews the historical context of a song which has been a Twickenham staple for years.

With the ongoing focus on the Black Lives Matters protests, the RFU has decided many who enjoy the song do not know its story and stands ready to address the issue.

It is believed to have its roots in American slavery, with its credited author being Wallace Willis - a freed slave from 19th century Oklahoma.

Moore, who played 64 times for England between 1987 and 1995, says he never understood why it became so popular among spectators.

"It can go for me; I hate it," he wrote on Twitter.

"This was sung in rugby clubs when I was still a colt and well before Martin Offiah and Chris Oti played senior rugby.

"It was sung because of the rude gestures that went with it and without any thought of its origins. The world has moved on and, rightly, things that were normal then should not necessarily be normal now.

"Had today's context be known then it might not have been sung. Amongst other reasons for the RFU encouraging people not to sing it, one of the main ones is that most people only know two verses and it's crap as a national song because it has no relevance to England.

"It should be celebrated in its rightful context."

The RFU said in a statement on Thursday: "The Swing Low, Sweet Chariot song has long been part of the culture of rugby and is sung by many who have no awareness of its origins or sensitivities.

"We are reviewing its historical context and our role in educating fans to make informed decisions."

Maggie Alphonsi, who won 74 England caps between 2003 and 2014, admits the song no longer "sits easy" with her.

"I remember singing it a lot when I was young, throughout my England career," she told Sky Sports News.

"It wasn't until someone told me about the song and its connections that I stopped singing it.

"It's not my place to tell people to stop singing it, because you have to educate people and let them make that decision.

"The song does not sit easy with me when I hear it, because I now know the connections with it. But I also know that people singing it today are not singing it to offend."