Dense fog halted all racing at Japan’s MotoGP on Friday with officials warning practice, qualifying and racing might have to be squeezed into a single day on Sunday unless the weather improves.

The lack of action at the mountainous Motegi circuit piles up frustration for rookie competition leader Marc Marquez, who is hoping to become the sport’s youngest champion but failed to clinch the world title last week in Australia following a disqualification.

With little hope of the weather clearing in the next 24 hours, race officials have warned they may need to bring in a dramatically revised one-day schedule.

Continued rain and heavy cloud cover is expected until Saturday afternoon, although the weather should improve on Sunday with some sunshine.

“If it’s not possible to practise at all tomorrow, we still expect Sunday’s weather to be significantly better,” race director Michael Webb told a media conference.

In such a case, “we have a provisional, heavily revised schedule that includes practice, qualifying and race on Sunday,” he said.

Drivers were left exasperated at Motegi circuit on Friday as dense fog grounded medical helicopters, forcing riders to remain trackside.

Without the possibility of chopper evacuation, the nearest accredited hospital is more than an hour away by ambulance.

“Without a helicopter here, with no viable alternative, we are not prepared to run in these conditions when there is a risk a seriously injured rider may not be able to adequately be treated,” Webb said.

“Rain is not a problem. It is the lack of visibility (for the helicopters).”

But Webb insisted any reduced racing schedule would not have an impact on the three racing classes.

“We are still committed to running all three classes at this Japanese Grand Prix,” he said.

Riders were forced to spend much of Friday waiting on the sidelines, signing autographs for fans.

Defending champion Jorge Lorenzo said he hoped to use the two remaining races of the season to derail Marquez’s march towards season victory.

“I think it is much better to stay calm and accept the circumstances. I hope the race will go ahead because two races is better than just one for us.”

The Spaniard is trailing Marquez by 18 points after the Honda rookie’s Phillip Island disqualification due to an astonishing team error.