Sirius Minerals gave investors a fright after warning that funding for its huge new mine in Yorkshire would take longer to arrive and the project may cost more than thought. Shares in the FTSE 250 company fell 25pc in early trade after it gave an update on plans to build the Woodsmith polyhalite mine in the North York Moors. But the stock regained ground to change hands 10pc lower at 29.5p. Sirius said the cost of digging the mile-deep mine would rise by $400m-$600m (£309m-£464m), on top of the previously estimated $3bn it still needs to raise in debt funding.