Despite repeated efforts to stamp out the problem in recent years, anti-Catholic abuse was repeatedly heard on the terraces during yesterday's game against Kilmarnock.
Chants of "F****n b******s" were heard during the first half of the match, followed by a rendition of the loyalist song The Billy Boys, which has been banned by Uefa for the line "we're up to our knees in F****n blood".
Later, some refereeing decisions which provoked controversy among Rangers supporters prompted a widespread chant of: "Who's the F****n in the black".
Before the match got under way, Rangers' administrators said that new information they had uncovered about club finances had "only added to the confusion" over the whereabouts of a £24.4 million payment made to Rangers by company, Ticketus, for the purchase of season tickets. Administrators added, however, that HMRC does not want to see a situation where the club is liquidated
Those responsible for sectarian chanting at yesterday's match were condemned for dredging up songs of "hate and ignorance" on a day when Rangers fans had packed into Ibrox to show their support for their crisis-hit club.
Peter Kearney, spokesman for the Catholic Church, said: "Sadly poisonous sectarian bigotry is all too often a part of some Rangers' fans identity. Despite repeated efforts by the club – and to their great embarrassment – anti-Catholic hostility is still alive and well among many Rangers fans."
Dave Scott, campaign director of the anti-bigotry charity Nil by Mouth, said: "This was a day when some Rangers fans came to show their true feelings for their club. I suspect any true supporter will be sickened to their stomach that others have chosen this day of all days to dredge up these songs of hate and ignorance."
A Scottish Government spokesperson said: "We deplore sectarian or bigoted chanting at any grounds or from any fans in Scotland."
Rangers did not respond to calls last night seeking comment on the issue of sectarian chanting.
Rangers administrators revealed yesterday that new information uncovered had led to a "pretty full understanding" of the takeover and financing of the club.
Administrators Duff & Phelps said they expected to make an announcement in the coming days after receiving details from the club's former lawyers.
A series of meetings with potential investors or new owners will also take place in the week ahead in a bid to save the "tremendous institution", the firm added.
But while the administrators said they remained confident of a "successful outcome" for the club, they also warned it was uncertain exactly what shape that will take.
Rangers were plunged into crisis on Tuesday when HMRC moved to put the club into administration over an upaid tax bill of £9 million, a debt owed to the taxman after owner Craig Whyte's takeover last May.
Whyte has insisted he has "nothing to fear" from any investigations into the club's affairs and can account for "every penny" which has gone in and out of the club.
Speaking ahead of the Rangers' match against Kilmarnock at Ibrox yesterday afternoon, joint administrator David Whitehouse said: "The key issue that has been talked about extensively is the whole financing of the original acquisition, the Ticketus money and level of capital that was introduced to the club.
"We got a load of information yesterday evening from the company's former lawyers and we have a pretty full understanding of what has happened. Until we get firm legal advice on that, we can't put it out, but there will be clarity on that next week."
He added: "The whole role of the previous management will be integral to understanding things. We are clearer as to what has happened in terms of the circumstances around the purchase and how the company has been capitalised."
Whitehouse said a series of meetings with potential investors or new owners would take place over the next week. "This club is a tremendous institution and it seems to us inconceivable that steps wouldn't be taken to try to save it," he added.
RANGERS are also awaiting the outcome of a tax tribunal which could leave them with a bill that could be as much as £75m.
Joint administrator Paul Clark said he remained confident HMRC does not want to see a situation where the club is liquidated.
He said: "We've spoken at length with HMRC ... If HMRC had been looking to close Rangers, they would have issued a winding up petition last week ... The message from HMRC is that they would like to work with us to make sure that Rangers survive. More meetings are scheduled for the coming week. They've been positive against the backdrop of neither party having complete information."
He added: "We remain confident that there will be a successful outcome for the football club. Exactly what shape that will take, we remain uncertain.
"But it's something that we are working with all parties to achieve a successful result. This is a football club and it's about playing football."
However, Clark said there was still a "lack of clarity" over the Ticketus deal: "Part of the information we've received in the past 24 hours has only added to the confusion. Payment (was) not made into a Rangers Football Club bank account. It went through a lawyer's bank account. We've got some visibility of funds."