But a spokesman for the Prince of Wales denies that he has been snubbed.
The Pontiff is due to meet the Queen and Prince Philip at Hollyrood House in Edinburgh, but Pope Benedict XVI turned down a request to meet Prince Charles at a separate venue the same day, according to a Sunday newspaper cited by the Belfast Telegraph.
"There were discussions between the Vatican and Clarence House about the possibility of having a separate meeting while the Pope was in Edinburgh, but there wasn't time in his schedule for that," said Prince Charles' spokesman quoted in the report.
The spokesman also denied that the Prince had rejected a subsequent invitation by the Pope to join him at an inter-faith event in London the following day.
Last year, the Prince and Camilla, both divorcees, were granted a private audience with the Pope in Rome.
SIC: CTHAUS