Travel industry chiefs have warned that holiday prices could go up - even for people who have already booked. There are fears of cancellations, delays and disruptions this summer as oil supplies are restricted by the war in Iran. And there are fears that prices of travel will go up to cover the rising cost of fuel. But industry experts have also raised the spectre of the price of existing holiday bookings going up. That means people who have already booked and paid for their holidays being