Rangers started their Group Stages campaign with a fine 2-2 draw in Spain against Villarreal before defeating Rapid Vienna 3-1 at Ibrox.
UEFA rules state visiting teams must get around five per cent of the capacity of the stadium, which means Rangers should give up around 2,500 to visiting teams in the Europa League Group.
But Rapid received only 1,400 tickets for their game and next visitors Spartak Moscow will get just 1,001 briefs.
Spartak contacted UEFA to complain about their allocation as they wanted their full quota.
But they have been informed UEFA have given Rangers permission to slash the allocation of visiting teams because the police view the games as high risk encounters.
A Spartak statement said: “Rangers awarded us only 1,001 tickets for the game in Glasgow. This is significantly less than the quota stipulated by the regulations, when the home team must allocate five per cent of tickets from the stadium’s capacity.
“Rangers have said it is because of local law enforcement agencies, who have made this match a high risk game and one that poses ‘heightened danger”.
“W wrote to UEFA, who have informed us there is nothing they can do.”
And a UEFA statement explained: “We took note of the exceptional decision of the local authorities in Glasgow to reduce the number of tickets for Spartak fans.
“All parties involved understand that security issues are of the highest priority for UEFA.”
Rangers have already slashed the allocation distributed to Celtic for just 800 for the first Ibrox Old Firm showdown this season on December 29 and Celtic did the same to Rangers for the Parkhead encounter in September.