The first shoe has dropped.

Camilla Parker Bowles, Prince Charles' longtime mistress, and Brigadier Andrew Parker Bowles, her long-suffering husband, announced yesterday that they are divorcing.

The news shot through London, fueling speculation that the split paves the way for Camilla and Charles -- who have carried on a steamy relationship for more than 20 years -- to live happily ever after. "Of course she is the love of his life; there is no denying that now, since he has made a clean breast of it himself," said Lord Charteris, Queen Elizabeth's former private secretary, in the current issue of the Spectator magazine.

The lovebirds were, of course, mum. Charles, who the BBC reported was told about the announcement in advance, was still skiing in Switzerland; Parker Bowles was reportedly staying with friends. A spokesman for the prince said yesterday that the heir to the throne and Princess Diana -- who separated in December 1992 -- have no plans to divorce.

British legal experts said there are no constitutional impediments to prevent Charles from ascending the throne if he divorces Diana and then marries Parker Bowles.

"The monarch may marry anybody provided they are not a Roman Catholic," said London School of Economics political scientist Rodney Barker. Camilla Parker Bowles is not Catholic, although her soon-to-be-ex-husband is. "There is nothing to prevent {Charles and Parker Bowles marrying}, and there is nothing in the law to prevent her from becoming queen."

But public opinion could prevent what the law cannot.

The Sun tabloid, which broke the divorce story, devoted its first seven pages to the news. The paper described Charles, Diana and Parker Bowles as "three tragic souls who face a future alone." Andrew Parker Bowles, who endured 21 years as England's most famous cuckold, was tagged "discreet, deceived, destroyed." And the paper wasn't shy about its own position: "Camilla will not become Mrs. Charles Windsor," it editorialized.

"The confidence of the public in the prince will be influenced by this divorce because for as long as Camilla was married they did not have to contemplate her ever becoming queen," royal expert Harold Brooks-Baker, director of Burke's Peerage, told Reuter.

"Everything he now does is very important, and the future of the monarchy now seems to rest on what Prince Charles decides to do," he said.

That future is already very much in doubt. A poll released Monday by the British newspaper the Guardian showed that 49 percent of British subjects believed they would see the end of the monarchy in their own lifetimes. Only 32 percent of respondents believed that the royal family would still exist in 50 years.

During the past year, the 25th anniversary of his investiture as the Prince of Wales, Charles attempted to rebuild his image by telling his side of the story. According to Jonathan Dimbleby's biography, "The Prince of Wales," published last year with the authorization of the prince, Charles revealed how his marriage to Diana crumbled, and admitted he had three affairs with Parker Bowles -- two after her marriage.

The candor has proven to be a mistake. A separate poll released Monday by Today newspaper concluded the rehabilitation was a failure -- only 16 percent named the prince among their favorite royals. "An astonishing 84 percent of people think that Charles has damaged the image of the Royal Family by confessing his affair with Camilla Parker Bowles," Today said.

But public opinion is clearly not enough to keep the prince from his lady love. Parker Bowles is 47 (a year older than Charles), horse-faced, dumpy and woefully unstylish. In short, she is nothing like the glamorous Diana. But it was Parker Bowles who was given an engraved bracelet on the eve of the prince's wedding to Diana, and Parker Bowles who received Charles' randy declarations of love (recorded from a cellular telephone) two years ago. The passion continues: The prince was seen sneaking out of Parker Bowles's country home outside London only a month ago.

Camilla met Charles at a polo match in the early '70s, and they dated until she grew impatient with his bachelor ways and married Parker Bowles in 1973. She and Parker Bowles have two children: Tom, 20, and Laura, 16. The divorce announcement comes one month after he retired as director of the army's Veterinary Corps.

In a statement released by their lawyers, the couple said: "Throughout our marriage we have always tended to follow rather different interests, but in recent years we have led completely separate lives. We have grown apart to such an extent that, with the exception of our children and a lasting friendship, there is little of common interest between us, and we have therefore decided to seek divorce."

Since they have already lived apart for two years, a provisional order for divorce will be granted this month and Camilla will be a free woman.

Now, it's up to the prince. Several tabloids reported that Diana was "indifferent" to the news of the divorce plans. The only thing holding up a royal "no-fault" divorce, according to several sources, is that Diana is reportedly demanding a 15 million pound (approximately $10 million) settlement. Lord Charteris said the royal family was resigned to the split. "Divorce will clear the air. And, yes, of course he will be king," Charteris said.

Neither a divorce nor Charles' remarriage would affect the status of Charles and Diana's sons, William and Harry, as the second and third people in line for the throne. But it could pose a problem for the monarchy's traditional role as head of the Church of England and "Defender of the Faith," a title that appears on British coins as the abbreviation F.D.

The Church of England traditionally had a blanket ban on allowing divorced people to remarry in the church, but some Anglican clergymen are now presiding over such marriages, said London School of Economics professor Patrick Dunleavy, who studies constitutional issues. He said church leaders are debating whether to lift the remarriage ban entirely. One thing seems clear: The 1990s are different from the 1930s, when Edward VIII was kept from his throne because he wished to marry a twice-divorced American. When the king attempted to marry Wallis Simpson in 1936, government, religious and public sentiment were absolute in their opposition to the union -- so much so that his government threatened to resign, which would have prompted an election in which the king's affair would have been the chief issue. Rather than face that, the king relinquished his throne "for the woman I love."

"We've moved a long way since the abdication crisis," Dunleavy said. "The only remaining question is whether you would want a higher standard for the head of the church" than for commoners.

Charles said late last year that should he become king he would prefer to be known as "Defender of Faith" -- not "the" Faith. But the Church of England may not attempt to block Charles' relationship with Parker Bowles, according to David Starkey, a historian at the London School of Economics. Archbishop of Canterbury George Carey and Prime Minister John Major "have gone out of their way to make it clear that a royal divorce has no impact at all on Charles' accession, and they have even implied ... that a royal remarriage would not be indigestible," he said.

But could the British people swallow it?

No, Majesty magazine Editor Nigel Evans told Reuter. "My feeling is that Charles will continue to see Camilla on an informal basis. I don't expect him to marry Camilla. The country is ready for a divorced monarch, but not a remarried monarch."

Even if the marriage were to take place, Parker Bowles might not be crowned queen.

"The spouse of the monarch does not have to be called queen," said political scientist Barker. "George IV never had his wife crowned because they were separated. She was kept out of {Westminster} Abbey during his {1821} coronation. It was quite a public scene."

CAPTION: Camilla Parker Bowles, Prince Charles' mistress, and her husband, Andrew, announced yesterday that they will divorce.