PRINCESS Margaret, younger sister of Queen Elizabeth, was suicidal as her marriage to the society photographer, Mr Antony Armstrong Jones, collapsed in the 1970s, it was reported yesterday.
Extracts in the Times newspaper from a biography of the queen said friends of Princess Margaret's were so alarmed at her mental state that they bugged one of her rooms.
Buckingham Palace declined to comment on the latest extracts from the book. It labelled earlier excerpts, which suggested that the queen's husband, Prince Philip had been unfaithful, as "tired, recycled speculation".
Princess Margaret, now 65, is seen in the British press as a tragic figure who never recovered from being forced in 1955 to sacrifice her love for the divorced war hero, Group Captain Peter Townsend, for the sake of royal protocol.
Her subsequent marriage in 1960 to Mr Antony Armstrong Jones started well (he has family connections with the Earl of Rosse of Birr Castle, Co Offaly, which the couple regularly visited). But by the 1970s they were leading separate lives.
Mr Armstrong Jones, now Lord Snowdon, refused to speak to Princess Margaret, spied on her through a hole in the wall and left insulting notes for her, the biographer, Sarah Bradford, said.
Princess Margaret suffered a brief breakdown in 1974 and her concerned friends arranged to bug a room where the couple had a confrontation. They sent the tape anonymously to a psychiatrist whose verdict was "This lady needs help soon."
On another occasion the princess is alleged to have telephoned a friend, threatening to throw herself out of the window. The friend rang the queen, who is said to have replied "Carry on with your party. Her bedroom is on the ground floor.
The marriage ended in divorce in 1978, breaking a 400 year old taboo on divorce in the inner circles of the British royal family.
Princess Margaret has never remarried and is now portrayed as a lonely woman with a fondness for drinking and smoking.
Bradford said the queen, who has a close relationship with her vivacious sister, has always felt guilty over the Townsend affair and was "desperately sad" when her sister's marriage failed.
"Like the rest of Margaret's inner circle she felt somehow that the unhappy princess's personal well being was a responsibility on all of them, Bradford wrote.
Bradford was allowed access to private royal correspondence as well as courtiers and close friends for her book Elizabeth, A Biography of Her Majesty the Queen. It is to be published in February.
Meanwhile, a retired royal footman has told how the young Duke of Edinburgh regularly took a woman friend for secret evenings at a country house, in the year after his marriage.
The duke would order drinks and sandwiches as he and his friend sat around a roaring open fire, and cushions would later be found on the floor, Mr Norman Barson told the Daily Mirror.
Mr Barson was employed as foot man at a house the royal couple used for weekends, Windlesham Moor near Ascot the newspaper said.