London, England (CNN) -- Speculation was intense Friday over where and when Prince William will marry Kate Middleton, with many predicting the couple will choose the iconic, thousand-year-old Westminster Abbey.
Middleton was photographed leaving the abbey Wednesday night with her parents, and British newspapers reported they had a private after-hours tour.
Westminster Abbey is the "venue of choice" for the wedding, the Daily Mirror tabloid reported Friday, and it even published a seating plan for the big day.
Ladbrokes betting agents seemed certain Friday that Westminster Abbey would be chosen, giving it 1/33 odds.
A CNN/ComRes poll out Friday found the British public largely positive about the engagement, which was announced Tuesday, a few weeks after William proposed.
Nearly eight in 10 of those surveyed -- 79 percent -- said they believe the engagement will be good for the monarchy.
Opinion was split, however, on who should succeed Queen Elizabeth -- whether Charles, who is next in line, or William -- though more respondents said William and Middleton would make a better king and queen than Charles and his wife, Camilla, Duchess of Cornwall.
In general, older people and those in higher income groups were more likely to take a traditional line and be more favorable toward Charles and Camilla, compared to those who are younger or in poorer income groups, according to the poll, which surveyed 2,015 adults in Britain between Wednesday and Friday.
Westminster Abbey was founded in 960, with the present Gothic church dating to 1245. Since 1066, it has been the "coronation church" -- the place where kings and queens are crowned when they ascend to the throne.
Its close ties to the monarchy mean it has also been the site of many royal weddings and funerals. Queen Elizabeth II married Prince Philip there in 1947, when she was still a princess; her father, King George VI, got married there in 1923.
The funeral service for Princess Diana, William's mother, took place there in 1997.
Another possible venue is St. Paul's Cathedral, where Diana married Prince Charles in 1981 in a wedding watched by millions worldwide. Ladbrokes gave that option 10/1 odds, and 16/1 odds for St. George's Chapel at Windsor Castle.
Others have also suggested as possible venues the London church of St. Clement Danes, the central church of the Royal Air Force, in which Prince William serves -- or the Chapel of St. Salvator at the University of St. Andrews, where the prince and Middleton met as students.
The palace has said the wedding will take place in the spring or summer of 2011.
The most likely month for the nuptials, according to Ladbrokes, was May, followed in order by July, June, then August.
British Prime Minister David Cameron wants a national holiday for the day of the wedding, his office at Downing Street said Friday, though the government must approve that first.