In addition, Charles will attend Friday's funeral in Rome, the prince's Clarence House office said.
Charles cut short his Swiss skiing holiday to attend a memorial service for the pope in London Monday afternoon, his office added. Parker Bowles also planned to attend the service at Westminster Cathedral, it said.
The Vatican earlier Monday confirmed that the funeral would be held on Friday, starting at 4 a.m. EDT.
The wedding had been scheduled for Friday, with the major ceremonial occasion, a service of blessing, set for 9:30 a.m. EDT.
The conflict posed a dilemma for Prime Minister Tony Blair, the Archbishop of Canterbury, and other British dignitaries who might be expected at both events, reports CBS News Correspondent Steve Holt.
Charles and Parker Bowles will be married in a civil ceremony in the town hall at Windsor, west of London, followed by a prayer service and dedication at Windsor castle's chapel.
Charles' impending marriage to Camilla Parker Bowles has locked British public opinion into a contradiction: people largely support the marriage but don't want her to be queen.
That popular sentiment apparently pressed Charles to declare that if he is crowned, Parker Bowles will become princess consort. The British government says, however, that if Charles is king, she automatically becomes queen — whether she uses the title or not.
Blame the confusion on the long shadow cast by Princess Diana, who died in a 1997 car crash in Paris.
Opinion polls indicate much of the public believes that Parker Bowles can have her man but not the title of queen.
It's as though Diana achieved her wish to be "a queen in people's hearts," and the public has no room for another.
The opposition to a Queen Camilla also reflects a view held by many in Britain that Charles cheated during his marriage to Diana and was the villain of the divorce — never mind that Diana had affairs as well.
"I'm not going to have it," added Rory King, 18. "It's just not right. She shouldn't be our queen."
But kings and queens are not elected, they simply accede to the throne through age-old rules of succession. British law says a monarch may not marry a Roman Catholic, but otherwise specifies no qualifications.
Charles' office insists that Parker Bowles can take a title of her choosing from a grab bag of her husband's offices: Prince of Wales, Earl of Chester, Duke of Rothesay, Earl of Carrick, Baron of Renfrew, Lord of the Isles and Great Steward of Scotland, and Duke of Cornwall.
Initially, Charles' office announced in February, Parker Bowles will be the Duchess of Cornwall. When he becomes king, "it is intended" that she will be Princess Consort.
Few missed the obvious point that intentions are not commitments and the wording left ample scope for a different decision at the time of a coronation, which may be many years away.
But the issue may be a problem at the coronation. Traditionally, the queen is crowned along with the king — though in the case of Queen Elizabeth II, her husband Prince Philip was not crowned and is not the king. That's because the husband of a female monarch is not allowed to be promoted along with her.
There is a precedent for the wife not being crowned. George IV locked his wife Caroline out of the coronation service at Westminster Abbey in 1820, but she was known as queen anyway.
George had a peculiar problem: he had married a Catholic woman, Maria Fitzherbert, before he married Caroline, so legally he was not entitled to become king. Moreover, he loathed Caroline.
A member of the House of Commons, Andrew Mackinlay, cut through the fog with a simple question to the government's chief legal officer: Will Prince Charles have a morganatic marriage? That means, would Parker Bowles have a lower rank than her husband?
No, said the government.
Thus, as of April 8, the wedding date, Camilla Parker Bowles will in fact be the Princess of Wales, though using the same title as Charles' first wife would horrify the legions of Dianaphiles. Similarly, if Charles becomes king, as his wife she will be queen, whatever she may choose to call herself.
Some of the public can accept that.
"I think she is wonderful and it is fine that she's going to be queen," said Susanna Goss-Clements, 40. "I think that her and Charles are good together and I wish them good luck."
Others don't care.
"I'm totally not interested in the subject of their marriage," Grace Campbell, 30, said.