Royal baby girl: Politicians from around the world congratulate the Duke and Duchess of Cambridge on the birth of their daughter

The prime ministers of Australia and New Zealand tweeted their support

Outside the Lindo Wing where the Duchess of Cambridge is due to give birth (AP)

Politicians from around the world took to Twitter to congratulate the Duke and Duchess of Cambridge on the birth of their new daughter.

Party leaders in the UK were joined by the prime ministers of Australia and New Zealand who sent messages of support to the the parents of the new royal baby, who is fourth in line to the throne.

The new baby will also be in the line to the thrones of 15 Commonwealth Realms, including Australia, New Zealand, Canada and a number of Caribbean islands. Many royalists in the realms where the Queen in currently head of state will be celebrating the news.

In the UK, David Cameron, Ed Miliband, Nick Clegg and Nigel Farage will all be hoping that the royal birth, just days before the General Election, will cheer the country and encourage their supporters to go out vote.

The Liberal Democrats leader was even invited into the home of a constituent while on the campaign trial to watch the news on TV.

The princess, who is fourth in line to the throne, was born at 8.34am at the Lindo Wing of St Mary's Hospital in Paddington, central London. She weighed 8lb 3oz.