Some of the most intimate thoughts of the late Queen Elizabeth, the Queen Mother, which she secretly recorded in the years before her death, will be aired for the first time next month.

The first ever first person material on the private thoughts of Queen Elizabeth will be included in the long awaited official biography by William Shawcross which is being published next month.

Transcripts of the hours of conversation, which were taped by Sir Eric Anderson, her friend and confidante, who is the former Provost of Eton College, were lodged in the Royal Archives at Windsor Castle.

Queen Elizabeth, who gave only one interview in her life when she was 22 and engaged to the Duke of York who was to to become George VI. But she talked privately for hours to Sir Eric, who taught the Prince of Wales at Gordonstoun, so that there was first person material – the late Queen Mother in her own words – for the biography. Their conversations covered the abdication and her attitude to fellow members of the Royal family and senior politicians.