LONDON (AP) — Practice makes perfect.
Kate Middleton and her bridesmaids, together with best man Prince Harry, rehearsed once more Thursday at Westminster Abbey, practicing the timing of the upcoming royal wedding to the last detail.
The rehearsal — the second in as many days — came as Middleton and Prince William released a message in their wedding program, saying they were deeply touched by the affection they have felt from many people since they became engaged.
"We are both so delighted that you are able to join us in celebrating what we hope will be one of the happiest days of our lives," they wrote. "The affection shown to us by so many people during our engagement has been incredibly moving, and has touched us both deeply."
The couple also released a new photograph taken by celebrity photographer Mario Testino — a warm black and white image of a comforting snuggle ahead of the big day.
Friday's wedding will offer pomp and circumstance on grand scale, with 1,900 invited guests, carriages and mounted troops of the Household Calvary. Rows of bold red, white and blue Union Jacks have been unfurled along the route. Street cleaners have scrubbed and swept the pavement along the route where hundreds of thousands are expected to gather on Friday.
Dozens of die-hard fans were camped out in tents and sleeping bags near the abbey on Thursday.
The wedding presents a security challenge for the 5,000 police officers on duty, who will be on the lookout for Irish dissident terrorists, Muslim extremists, anti-monarchists, protesters and hooligans who might blight the royal spectacle.
Scotland Yard Police Commander Christine Jones said Wednesday there has been no new terror threat but considerable Internet chatter.
"Our operation has been meticulously planned, and we have thought through and planned for a huge range of contingencies," she said.
A wide range of police will be on patrol Friday: officers on motorcycles, escort specialists, dog handlers, search officers, mounted police, protection officers and firearms units.
Thousands of people are expected along the parade route Friday, a snaking path of less than a mile (two kilometers) from Westminster Abbey to Buckingham Palace, where the new royal couple will appear on the balcony for one of the most anticipated kisses in decades.
In October, the U.S. State Department advised Americans to be wary amid reports that terrorists were planning a Mumbai-style attack on a European city. More than 160 people were killed in that 2008 attack, when gunmen fired on crowds in a shooting spree.
A warning for American visitors to Britain is due to expire the day after the wedding and U.S. officials said there was no plan to renew it.
"That threat is still being investigated but there is no intelligence to suggest a highly organized threat to the royal wedding," a western intelligence official told The Associated Press, speaking on condition of anonymity because of the sensitivity of his work.
But with the ceremony just a day away, attention turned to the service itself. The program showed that Middleton will not promise to "obey" her new husband in her vows but instead to "love, comfort, honor and keep" him.
Middleton will walk up the aisle at the Abbey to the sounds of "I was glad," the anthem setting of Psalm 122 composed by Sir Charles Hubert Hastings Parry for the coronation of King Edward VII in 1902. The anthem was also sung at the wedding of William's parents, Prince Charles and the late Princess Diana.
The hymns — "Guide me, O thou great redeemer," ''Love divine, all loves excelling" and "Jerusalem" — are standards at Church of England marriage ceremonies.
"Guide me, O thou great redeemer" was also the final hymn at Diana's funeral in Westminster Abbey in 1997.
The newlyweds will leave to the march "Crown Imperial" by William Walton, which also figured in Charles and Diana's wedding.
A spokesman at St. James' Palace said Middleton was familiar with classical music, but had "a lot of input" from Prince Charles.
"They spent a a lot of time listening to the music together on iPods," said the royal functionary, speaking on condition of anonymity.
But as wedding excitement heated up, the weather in London started cooling down. The royals may want to pack extra umbrellas, as forecasters are predicting it might rain.
The Meteorological Office has reported that the day will start off relatively gray and dry with low clouds across London. During the course of the morning, sunny spells are expected to seep through and the chance of showers will rise to 30 percent around noon, the time when William and Kate are expected to emerge from the Abbey a married couple.
Associated Press Writers Paisley Dodds and Aaron Edwards contributed to this story.