Prime Minister David Cameron said news that the Duchess of Cambridge had gone into labour was "very exciting".
Mr Cameron said, "Best wishes to them. A very exciting occasion and the whole country is excited with them. So, everyone's hoping for the best."
More top news
Heavy rain spreading eastwards overnight
The terminally ill boy's mother, Connie Yates, burst into tears as a lawyer reveals Charlie's latest brain scan makes for "sad reading".
White House Press Secretary Sean Spicer has resigned after just six months, it has been announced.