Duchess of Cornwall: As Her Majesty falters, enter Camilla the Queen in waiting: Duchess looks majestic as Prince Charles is expected to perform more of his mother's duties Wearing a dazzling tiara, Camilla looked like Queen in waiting Prince Charles attended his first State opening in 17 years By Louise Eccles She has been delivering seamless speeches to the nation for more than 60 years. So when the 87-year-old Queen stumbled over her words during the State Opening of Parliament yesterday, she might just have been having an off day. But - as she prepares to scale back her public duties - some will see it as a symptom of her advancing years. Looking regal: Camilla and Charles arrive dressed in dazzling outfits In a rare slip-up, the Queen faltered over half a dozen words during the seven-and-a-half minute oration at the Palace of Westminster in front of peers and MPs. Two minutes into her 60th speech for the Opening of Parliament, she tripped up over the words "infrastructure" and "availability." Perhaps unnerved by her earlier stumbles, she then appeared to stammer over the words "take" and "contribute," before struggling with the word "government" twice towards the end of the speech. Prince Charles, who was attending his first State Opening in 17 years, is expected to take on more of his mother's tasks - and yesterday his wife Camilla in a dazzling tiara looked very much like a Queen in waiting at his side. The Duchess of Cornwall wore a champagne-coloured lace and silk gown, with a dramatic train, by her favourite designer Bruce Oldfield. Glowing! The Duchess of Cornwall flashes a smile - and her beautiful jewellery - as she leaves after the State Opening The Prince of Wales and the Duchess of Cornwall watched the State opening after it was announced that Charles would take on some of the Queen's duties Queen Elizabeth accompanied by Prince Philip, the Duke of Edinburgh, Prince Charles, and Camilla, Duchess of Cornwall at the State Opening of Parliament A Royal occasion: A spokesman for Clarence House played down the significance of their attendance, saying the pair's diaries were clear She accessorised her floor-length gown with her own four-string pearl necklace, pearl drop earrings and white gloves - plus a dazzling diamond-encrusted Boucheron tiara, which once belonged to the Queen Mother and which was loaned to Camilla by the Queen. She arrived with Prince Charles, who wore his Admiral of the Fleet uniform, in a glass carriage in their own procession, ahead of the Queen. A spokesman for Clarence House played down the significance of their attendance, saying: "The Prince of Wales often supports the Queen on state occasions, and his and the duchess's diaries were clear on this occasion." The visit followed the surprise announcement by Buckingham Palace on Tuesday that, for the first time in 40 years, the Queen will not attend the Commonwealth Heads of Government Conference. Instead, Prince Charles will take her place at the two-day event in Sri Lanka, in November. he Duchess of Cornwall wore a champagne-coloured lace and silk gown, with a dramatic train, by her favourite designer Bruce Oldfield Camilla accessorised her floor-length gown with her own pearl necklace, pearl drop earrings and white gloves ¿ plus diamond-encrusted Boucheron tiara, which once belonged to the Queen Mother Camilla was seen with her husband in a carriage as they travelled to Prince Charles' first State Opening in 17 years Dressed in an ivory gown and wearing the diamond-encrusted Imperial State Crown, the Queen looked resplendent as she delivered the speech from a gilded throne Yesterday, the Queen was driven from Buckingham Palace to Parliament in a horse-drawn carriage, escorted by mounted members of the Household Cavalry, for the state opening. Dressed in an ivory gown and wearing the diamond-encrusted Imperial State Crown, which includes 2,868 diamonds, 273 pearls, 17 sapphires, 11 emeralds and five rubies, she looked resplendent as she delivered the speech from a gilded throne in the House of Lords. The State Opening of Parliament marks the formal start of the parliamentary year and a speech by the monarch can be traced back as far as the 16th century. The Queen has missed only two such ceremonies during her reign - in 1959 when she was pregnant with Prince Andrew and in 1963 when she was expecting Prince Edward. She still conducts more than 300 engagements each year, although she is understood to be gradually scaling back her diary. Palace aides have denied that the Queen's recent ill-health, when she was hospitalised in March with gastroenteritis, has influenced the decision to cut back on her overseas travel. As well as looking after her own health, she is said to be concerned not to put too much strain on her husband, Prince Philip, who will be 92 next month and still accompanies her on most trips. Prime Minster David Cameron and opposition Labour Party leader Ed Miliband, followed by LDeputy Prime Minister Nick Clegg, walk through the Members' Lobby to listen to the Queen's Speech Surrounded by Lords and politicians, the Queen delivered the State Opening speech. She has missed only two such ceremonies during her reign