The Met said that because TV commitments prevented the “high-risk” fixture from starting by 16:45 on the rearranged date – which for safety purposes is the agreed cut-off time with London clubs on weekends – an alternative solution had to be reached.

“Our first priority in policing football – and the increasing crime and disorder associated with it – is the safety of fans and those who live and work in the local community,” said the Met Police.

“This can require significant resources and we have to balance this commitment against our many other policing responsibilities across London.

“While we accept that this [decision] may disappoint and inconvenience some fans, it was not the only option available to the clubs and was not a decision taken directly by the police.”

United have already sold their initial away allocation of 2,994, and the club says it is “urgently considering options” as it seeks to remove 624 sold tickets.

A MUST statement said: “We are now considering legal action against the Met Police on behalf of our fans affected by this decision to reduce our allocation, after tickets have been sold to fans in good faith, many of whom will have booked travel.

“A match reaching a point a few weeks before being played without a confirmed time is a terrible precedent which could have easily been avoided.

“We find it abhorrent and a disgraceful precedent that an away allocation has been cut weeks before a game and after tickets have been allocated.”

The match, initially scheduled for 16:30 on Sunday, 23 October, was moved to the Saturday because of Chelsea’s Champions League fixture the following Tuesday.

The kick-off time has been confirmed, 15 days before the date of the game, following extensive talks involving both clubs, the Premier League and the Metropolitan Police.

Manchester United said: “While we are very disappointed by this outcome and believe it is unjustified, it is clear it is a final decision.

“Unfortunately, the police have continued to insist on a reduction. However, we have succeeded in increasing the allocation to 2,370.”

MUST said it is consulting lawyers over the matter and urged the Premier League to look at policing, away allocations and late decision-making.

“This fixture has been a shambles by the authorities collectively, and regardless of any buck passing, as usual it’s fans left as the losers from it all,” said MUST.

Chelsea Supporters’ Trust said it stands with MUST and also criticised the decision.

“Kick-off announced with 15 days’ notice and away allocation reduced. This confirms that as long as the game can be broadcast, supporters are disposable,” said CST.

“This is an insult and sets a dangerous precedent. We stand with Manchester United Supporters’ Trust and the 624 supporters who will have their tickets cancelled.”