BATTLE has been joined over the shape of Labour’s next Budget as Britain’s economy continues to struggle.Union leaders are set to meet new Chancellor John Healey as he prepares his first Budget, to be delivered next month, and to press for a radical change of direction.They are set to argue that Mr Healey’s choices will set the course for the rest of the Labour government’s term.The meeting comes after the Bank of England left interest rates unchanged at 3.75 per cent.