The Electoral Commission has announced that Vote Leave has been designated as the official lead campaign urging Britain to leave the European Union, in the run-up to the June referendum.
The decision will allow the group to spend up to £7m it has raised itself; and it will also be given public funding to send one mailshot to every household in the UK.
Vote Leave, which has the support of cabinet ministers including Michael Gove, Boris Johnson and Chris Grayling, and is chaired by the Labour MP Gisela Stuart, had been widely expected to be anointed.
The decision may be contested by Leave.EU, the group funded by the businessman Arron Banks, in which the UK Independence party leader, Nigel Farage, plays a prominent role.