Waitrose has cancelled large parts of its online shopping service after the ongoing fuel crisis brought most of its delivery fleet to a halt.Online orders of flowers and organic foods have been suspended, with grocery and wine supplies to be determined on a branch by branch basis. While in-store supplies remain relatively unaffected, online deliveries have been severely hit because delivery drivers rely on local fuel resources, rather than Waitrose's own fuel reserves, according to a spokesman for the retail group. Other retailers are also suffering from the fuel shortages, with Tesco setting up a 'fuel crisis group' to consider ways of preserving supplies for home deliveries. A Tesco spokesman told silicon.com: "It's an hour by hour, day by day thing. We're using the same fuel supply for dot-com and in-store delivery lorries. We have supplies until Friday. If it goes on longer we will have to reassess." He added: "We have had supply problems in our stores which will have had a minor knock-on effect on online deliveries. But we have notified customers if we cannot fulfil orders." Sainsbury's claims it is too early to assess the impact of the fuel crisis on its online delivery service. The company confirmed, however, that overall sales jumped 35 per cent yesterday as panicked customers stock up in anticipation of a fuel-free weekend.