Australia's Prime Minister Kevin Rudd and his New Zealand counterpart John Key have welcomed the arrival of the royal baby.
Mr Rudd said it was a time for "rejoicing", while Mr Key said it was a "momentous day" for the Duke and Duchess of Cambridge.
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The Government scheme would benefit those aged under 40 but will only run for five years.
Joseph Rowntree Charitable Trust and the Roddick Foundation are under investigation by the watchdog over grants made to Cage.
The Duke of Cambridge became a fearsome samurai warlord - at least temporarily - when he visited the set of a long-running Japanese drama.