Economic Secretary to the Treasury, Chloe Smith, said the freeze on fuel duty announced today would be funded through underspend in Government departments, but would not be drawn on which departments.
She told BBC2's Newsnight:
It is not possible to give you a full breakdown at this point because the figure is evolving somewhat,
More top news
The victim, a man in his 40s, is being treated in hospital for "life-changing" injuries after the attack by two men who remain on the run.
Heavy security presence as 64,000 fans gather at the Stade de France stadium for the Six Nations rugby match between France and Italy.
Today's rain will clear into the North Sea tonight, but winds will stay strong, with showers feeding in to the north and west.