With the show just a week away, and the latest reports indicating increased activity in the volcano, the possibility of a repeat of the transport chaos that affected last month's London Book Fair cannot be ruled out.

However, Ipex event director Trevor Crawford stressed that while some flights had been delayed, most airlines were operating a good service.

"Air space is largely open over Europe and people are flying. Also, if you look at the slightly longer-term forecast for the coming week, it includes a bout of rain, which I'm told will help to reduce the ash cloud," he said.

"All we can do is watch it on a day-by-day basis. Our hotline is still open so if any visitors have any concerns they can contact us for the latest information."

IIR's hotline, which was launched last month at the height of the travel disruptions, can be reached on 020 3377 3730.

According to reports, the current wave of eruptions is emitting ash up to 6,000m (20,000ft) and disruptions could carry on into next week if northerly winds continue to bring ash into the European air traffic zone.

Flights in Portugal, France, Austria, Scotland, Ireland, Italy and Germany were all disrupted over the weekend, with flights grounded at some airports, including Munich in southern Germany.

Last month, ash from the Eyjafjallajökull volcano shut down airspace across Europe for five days, although transport secretary Lord Adonis later admitted that this had been "too cautious".