Cameron leads the way as congratulations flood in for couple

The Prime Minister, who revealed that he had slept on the Mall in London on the eve of the wedding of Prince Charles and Diana in 1981 in order to secure a good view, said the forthcoming Royal wedding would unite Britain and revealed the Prince was "thrilled" when he rang him to congratulate the couple on their engagement.

"It is incredibly exciting news and I'm sure that the whole country will want to pass their very best wishes to the happy couple, and wish them an incredibly long and happy life together," he said.

The Archbishop of Canterbury, Dr Rowan Williams, expressed his "delight" at the news.

Tributes followed from prominent figures in Scotland, where William and Miss Middleton met at St Andrews University, and Wales, where the couple will continue to live.

Scotland's First Minister Alex Salmond said: "Of course this was a match made in St Andrews, and everyone in Scotland will join with me in wishing the Prince and Ms Middleton every happiness as they look forward to their wedding day, and a long and fulfilling married life together."

A St Andrews University spokeswoman said: "We are absolutely delighted for William and Kate and their families.

"St Andrews is a special place – one in 10 of our students meet their future partner here, and our title as Britain's top match-making university signifies so much

that is good about this community.

"2011 will see the launch of our 600th anniversary celebrations and we will be proud to share our anniversary with the royal couple.

"We hope that they will take the opportunity to return to Scotland and join us in celebrating the romance of St Andrews."

Welsh First Minister Carwyn Jones said: "I'm very pleased to hear that they plan to begin their married life in north Wales. I am sure that I speak for the people of Wales in wishing them the best for their future happiness."

Stacey Adams, chief executive of charity Raleigh International, which ran expeditions that William and Miss Middleton took part in, also congratulated the couple.