Saints will face an Allianz Park date in the Champions Cup quarter-finals after Saracens confirmed they would be able to host the match at their home ground.
The stadium currently only holds 10,000 and would need another 5,000 seats to meet the requirements for a knockout clash in Europe’s premier club rugby tournament.
And it seems Saracens will be able to bring in some temporary seating for the clash with Saints, which will take place on April 9, with a kick-off time of 5.45pm.
“We’re delighted that we have been able to host the game here in north London and in the Borough of Barnet,” said Saracens CEO Heath Harvey.
“We’re extremely proud to call Barnet our home and to be able to host a game of this magnitude is great news for Saracens, the Borough, and north London as a whole.
“We have had some very detailed discussions with the Borough Council, and we thank them for their support throughout the process.
“A European Champions Cup quarter-final against Northampton is a mouth-watering prospect, and we are looking forward to the game in April.”
The winners of the game between Saints and Saracens will meet Wasps or Exeter Chiefs in the semi-finals on the weekend of April 23/24.
This season’s showpiece takes place at the 59,000-capacity Grand Stade de Lyon on Saturday, May 14.