Even though the officials will be in an air-conditioned room surrounded by monitors, the unusual move has been defended by former referee Pierluigi Collina.
Collina, who chairs FIFA's Referees Committee, suggests the officials' stress levels justify them wearing the full kit.
"It’s because they sweat like they do on the pitch," the 58-year-old Italian told reporters.
"It’s not like watching a game on the couch while drinking coffee. It’s very stressful, so they can’t be dressed like a clerk."
Another rule tweak which has sparked lively debate is the committee's decision for referees not to make tight offside calls so that VAR can effectively override them.
Collina added: "If you see some assistant referee not raising the flag, it’s not because he’s making mistakes. It’s because he’s respected the instruction to keep the flag down.
"They were told to keep the flag down when there is a tight offside incident and there could be a very promising attack or a goalscoring opportunity because, if the assistant referee raises the flag, then everything is finished."
The World Cup starts on Thursday when Russia face Saudi Arabia at 4pm BST.
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