Scottish Rugby believes it has a legal case against the game's governing body as it seeks to ensure their decisive World Cup match with Japan goes ahead.

World Rugby will make a decision on Sunday morning about whether the match in Yokohama can go ahead as the host nation prepares for Typhoon Hagibis.

It has already cancelled two Saturday games and declared them a draw, but a repeat could mean Scotland's exit.

But SRU chief executive Mark Dodson says "legal opinion unravels" its case.

Gregor Townsend's side lie third behind Ireland and Japan in Pool A and must beat the hosts - and take four more points than them - to progress to the quarter-final stage unless the Irish lose to Samoa.

World Rugby rules state that "where a pool match cannot be commenced on the day in which it is scheduled, it shall not be postponed to the following day and shall be considered as cancelled. In such situations, the result shall be allocated two points each and no score registered".

"For World Rugby to simply state that the game has to be cancelled goes against the whole sporting integrity of the tournament," Dodson told the Today programme on BBC Radio 4.

"World Rugby have pointed us back to the participation agreement and that it is clearly stated there. We've had a legal opinion and then we've taken a leading sports QC opinion in London that challenges that and unravels the World Rugby case."

World Rugby hopes the worst of the typhoon will have passed by Sunday and that the game will go ahead, but Dodson is angered by its refusal to consider moving the game to another time or venue.

"We've been preparing for this tournament now for the last four years, our guys are over 100 days in camp, we've played three games already and the fourth game in this particular case is pivotal," he added.

"My view is that we're not going to let Scotland be the collateral damage for a decision that was taken in haste."