Sir Richard Branson is to put £200m of his own money into the rescue of Northern Rock as part of the deal he sealed during a weekend call from his private Caribbean island.

The Virgin boss called Alistair Darling, the UK chancellor, hours before a final decision was made by the board of the bank to name Sir Richard’s consortium – which also includes Wilbur Ross, the US distressed-debt investor, the hedge fund Toscafund and First Eastern Investment group – as preferred bidder.