Sarah Ferguson, the former wife of Prince Andrew, will not be invited to the wedding of Prince William and Kate Middleton, her spokesperson has confirmed.
However, the Duchess of York's daughters Princesses Beatrice and Eugenie, William's cousins, are expected to be among the guests at Westminster Abbey in London.
About 1900 invitations to the wedding on 29 April have been sent out, ahead of what is the most eagerly anticipated marriage since William's late mother Diana married Prince Charles in 1981.
The spokesperson told British newspaper the Daily Telegraph that Sarah "never expected to be invited or to attend" and that she will be overseas at the time.
The Duchess of York has long been viewed as somewhat of an embarrassment to the royal family, AFP reports, particularly last year when she was caught in a newspaper sting apparently trying to sell access to her former husband.
She apologised for what she said was a "serious lapse in judgment" and in a later interview with American talk show queen Oprah Winfrey blamed alcohol and money problems.
Guests ranging from family and friends to foreign dignitaries, diplomats, soldiers and charity workers have been asked to attend the service, but no names have been revealed.
About 600 will get the opportunity to enjoy a lunchtime reception with the Queen at Buckingham Palace, while a group of about 300 will be treated to an evening banquet hosted by Prince Charles.