The Queen will not attend the civil marriage ceremony between the Prince of Wales and Camilla Parker Bowles at Windsor Guildhall, Buckingham Palace said last night. A spokesman said she wanted to keep the occasion "low key". The Queen will attend the service of prayer and dedication presided over by the Archbishop of Canterbury, Dr Rowan Williams, at St George's Chapel, Windsor castle, after the civil ceremony conducted by a registrar. The spokesman said: "The Queen is aware that the prince and Mrs Parker Bowles wanted to keep the occasion low key. "The Queen and the rest of the Royal Family will, of course, be going to the service of dedication at St George's Chapel. She is very pleased to be giving the wedding reception at the castle." The announcement is a further blow to the prince who has seen his wedding plans for April 8 fall apart. It will be interpreted by many as a snub. There have been reports that the Queen was horrified at the prospect of the heir to the throne marrying in, effectively, a town hall. There has been speculation that she regarded it as "common". Asked if it was a snub, the Palace spokesman replied: "The Queen is attending the service of dedication and paying for the reception. This is not a snub." He declined to say whether the police had advised her against attending on security grounds. Sticking to his line, he said: "Clearly if the Queen were to attend, the occasion would no longer, by definition, be low key." An aide said the Queen did not always attend family weddings, citing the example of the marriage of the Duke of Gloucester's elder daughter, Lady Davina Windsor, to a Maori builder. When it was pointed out that this was a rather distant relation compared with the Queen's eldest son and heir, he said: "It was the prince and Mrs Parker Bowles's decision to keep this low key". A spokesman for the prince said that details of the civil ceremony had yet to be finally settled. But it is understood that the four children of the couple will attend and other members of both families may also be at the Guildhall. A Clarence House spokesman said that Prince William was expected to be an official witness and possibly Prince Harry as well. The Queen's decision adds to the controversy surrounding the wedding, which was first due to be held in Windsor Castle but was switched to the Guildhall because of problems over a licence. Despite taking legal advice from four sources, aides failed to realise that, if the castle were granted a licence as an approved wedding venue, it would remain licensed for members of the public to marry there, making it the most popular wedding venue not just for Britons but also possibly tourists. The image of the Queen and Prince Philip and most of their close family traipsing into the town hall in front of the crowds expected to turn out is understood to be too demeaning for her senior aides to countenance. The main chamber in the Guildhall can accommodate only 100 people, forcing the prince and Mrs Parker Bowles to be selective about who will be able to attend. There will be 700 guests at the church service and at the reception in the State Apartments for the prince and Mrs Parker Bowles, who by then will be HRH Duchess of Cornwall. The Queen's decision will be a blow to her former Keeper of the Privy Purse, Sir Michael Peat, who is now the prince's private secretary. Sir Michael believed he had come to an ideal compromise when the licence problem emerged. Dr David Starkey, the constitutional historian, said the Queen's decision was "unprecedented". "One can only speculate on the reason. It could be security, that she does not approve, or that she does not care - a position that would unite her with the majority of her subjects."