Motorsport boss Max Mosley has accused BAR of making a "crude and primitive" attempt to break Formula One rules.
BAR were banned for two races for running an underweight car and using a secondary fuel tank at last month's San Marino Grand Prix.
"You have got to be crazy to do it. People don't do that sort of thing in Formula One any more," said Mosley.
"It's the sort of thing people do in a club race. It's crude, it's primitive, it's not sophisticated electronics."
Mosley, who is president of F1's ruling body, the FIA, claims he was aware of paddock gossip over the winter which suggested BAR were running cars which did not meet regulations.
BAR have strenuously denied any wrongdoing and insist their cars were never under the 600kg minimum weight requirement at Imola.
"Everybody who was really in the know in Formula One strongly suspected something was going on," said Mosley.
BAR argued that they did not break the rules because nowhere is it explicitly written that a car must weigh 600kg or more when drained of fuel.
But they said they had decided not to try to overturn the two-race ban in order to avoid damaging Formula One.
Drivers Jenson Button and Takuma Sato now have no points and will have to sit out Sunday's Spanish Grand Prix and the race in Monaco on 22 May.
And team boss Nick Fry revealed that missing Monaco will trigger penalty clauses in BAR's sponsorship contracts.
"This is going to cost a huge amount of money. I haven't calculated what it is at the moment. But I can confidently say this is going to add up to $10m (approx £5m) at least," said Fry.
BAR, who employ 600 people in the UK, are now packing up from Barcelona.
They also fear the punishment will make their battle to keep hold of British driver Button, who tried to leave for Williams last year, harder.
"It's now more complicated and more difficult than we first envisaged but we want Jenson for 2006 and beyond," said Fry.
Although details remain confidential, Button is understood to be free to join Williams in 2006 if he is not within a certain percentage of the championship lead by a given point in the season.
Despite accepting that they will not be able to overturn their punishment, the team made it clear they would not let the matter lie.
"BAR are so enraged with the decision that they have decided to publish their entire submission to the court of appeal on their official website," a statement said.
It also confirmed that it would discuss the ramifications of the decision with its fellow teams and engine manufacturers.
"We are going to ensure we are completely transparent," said Fry.
"We are publishing everything from the court of appeal. Even though we are giving away some information to our competitors it's better that we do that to show everyone what we've done because we have nothing to hide."