Teams are anxious to get their cars back to factories but despite the delay, Formula 1 boss Bernie Ecclestone has said he is confident the Spanish Grand Prix, the first European race of the season, will go ahead as planned on Sunday 9 May.
England will stick to their original intentions to fly from Gatwick to the Caribbean on Sunday.
Widnes Vikings' Challenge Cup tie against Lezignan has been rearranged for Thursday after the French side's flight to the UK for Saturday's original meeting was cancelled.
Lezignan have already set off from the south of France on a coach trip to the Stobart Stadium.
However, the Championship match on Thursday between Featherstone and Toulouse has been postponed as the French side only made it home on Monday after Saturday's Challenge Cup defeat at St Helens.
Catalans Dragons' next Super League fixture is against Warrington on Sunday.
Carl Froch's defence
of his WBC super-middleweight title against Denmark's Mikkel Kessler in Herning will be unaffected by the travel disruption - the Nottingham fighter flew into Denmark by private jet on Tuesday afternoon.
Rendall Munroe's WBC super-bantamweight eliminator against Victor Terrazas is also set to go ahead in Coventry on Friday, with the Mexican making a marathon journey to England by plane, car and train.
The Moroccan Golf Classic, due to start at the Pullman Magazan course in El Jadida on Wednesday, has also been postponed.
But the Ballantine's Championship in South Korea on the full PGA European Tour is unlikely to be affected, with the majority of players already in Asia after the Volvo China Open.
Organisers are monitoring the air pollution levels in London and say analysis of the dust material indicates it does not contain material that is seriously harmful to health.
Oliver Townend has arrived in Kentucky after a marathon journey and will bid to land the Rolex Grand Slam and the £230,000 reward on offer.
Having won at both Badminton and Burghley, the Yorkshireman is chasing the final leg of the Slam - and the lucrative prize - in Lexington.
His trek began in Ellesmere, Shropshire
and has taken in Crewe, London and Paris, from where he caught a taxi to Madrid - a 14-hour journey costing around £1,600 - and then a plane to Miami and an internal flight.
The postponement means the Spanish MotoGP in Jerez, Spain on 9 May is now next up in the calendar.
Punchestown in Ireland
are not expecting the volcanic ash cloud crisis to affect the British raiding party at their five-day meeting, which started on Tuesday.
Seven British-trained contenders ran at the picturesque Kildare track on the opening day.
Somerset-based champion trainer Paul Nicholls sent over Twist Magic and Denman by ferry.
Team Sky's Bradley Wiggins was among those forced to miss the Amstel Gold race, the first of the Ardennes Classics, in the Netherlands on Sunday.
Carlos Sastre, Alejandro Valverde and Luis Leon Sanchez were also missing as Belgian Philippe Gilbert took victory.
The start of the European Gymnastic Championships in Birmingham has been delayed by a day, with the qualifying round set to begin on Friday.
'Remarkable' gymnasts overcome ash cloud
Organisers have sent buses to Paris, Brussels, Amsterdam and Bremen to pick up some of those taking part.
Russia, Belarus and Ukraine have pulled out, while Portugal had earlier announced their intention to withdraw but are now set to arrive on Wednesday. Other teams arriving late include Hungary, Greece, Latvia and Bulgaria.
Britain's trampolining, tumbling and DMT gymnasts, meanwhile, have embarked on a mammoth 40-hour-plus coach trip to take part in their European Championships in the Bulgarian Black Sea port of Varna.
Great Britain's judo team will make a 900-mile road trip to compete in the Senior European Championships in Vienna, which run from Thursday to Sunday.
Kelly Edwards, Colin Oates and James Millarwill are all in action on the opening day of the tournament.
The squad's Russian, Bulgarian, Lithuanian and Slovenian counterparts were all preparing for the event at the British Judo Performance Institute in Dartford, Kent, and they, too, have decided to make the arduous journey - the Russians by train and the others on buses.
Great Britain's opening match against Croatia at the Ice Hockey World Championships on Saturday was delayed after the team had to swap a flight for a 26-hour bus and train journey to Slovenia.
Despite not arriving Slovenia until two hours before the game, GB showed no signs of travel fatigue as they coasted to a 4-1 win.
International Olympic Committee chiefs have been forced to carry out their review of London 2012's preparations via telephone this week.
IOC co-ordination commission chairman Denis Oswald and Olympic Games director Gilbert Felli had been planning to fly to London for the review.
The final leg of the Diving World Series, due to be staged in Sheffield this week, was rearranged to take place in Veracruz, Mexico, following the conclusion of the second leg there on Saturday.
Belle Vue Aces riders Hans Andersen, Peter Karlsson and Patrick Hougaard are stuck in Scandinavia ahead of the Elite League fixture against Ipswich, although German signing, Tobias Kroner, has managed to get to England and will make his debut.
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