After the House of Lords finally dropped its opposition to ID cards last week, Phil Booth, the national co-ordinator of NO2ID, said the Government faced a public rebellion of poll tax proportions.
"We have already received about 14,000 pledges to support our fight by donating money to our legal defence fund," he said. "This will be used to help pay for the legal costs of those who refuse to get a card. We thought it would take us months to get to this stage, but it only took five weeks."
Booth said the organisation has the support of judges and lawyers. "If we had to pay the normal lawyers' rates, it would be impossible," he said.
"But we have several who are prepared to take on the cases of those who will not comply."
A recent poll showed that 8.5 million people are now deeply opposed to the cards, compared with only three million when the idea was first mooted.
"They need to get the entire population to be fingerprinted for it to work, otherwise it will just be a chocolate teapot," said Booth. "What are they going to do - frogmarch people up to get their prints taken?
"This is far worse than the poll tax because it gets into your life, for the rest of your life. We are over halfway to getting the support of the 17 million people who protested against the poll tax - we are way ahead of schedule."