After months of media stirring and the recruitment of 150,000 Australians, Australia's biggest ever class action, in terms of numbers of litigants, has now officially begun.ANZ will face a class action brought by 27,000 of its customers claiming repayment of exception fees plus interest. Preliminary court hearings are set for 4 November in the Federal Court in Melbourne.Maurice Blackburn principal, Ben Slade, said he hoped the lodgement of documents yesterday and the announcement of action against ANZ would boost the numbers of people coming forward to take part in the class action."We have 27,199 people and businesses representing 40,000 accounts with ANZ."We don't have more ANZ customers than the other big four banks."We just wanted to start with a big four bank and this is the one where we were ready to go first. Other claims will follow against other banks in the next two months," said Slade. "We are still looking for more people. We have 213,000 accounts across all 12 banks we are targeting - that's about 150,000 people."Slade denies that Maurice Blackburn are falling short of the numbers they need to force a settlement or generate fear in the defendant banks."I think we thought at the beginning we need about 230,000 accounts and around the 150,000 people number so we have enough to keep it going."Of course we have just a slice of the total number of people affected. But with IMF we definitely have the resources to see this through all the way if necessary," said Slade.IMF has an investment portfolio worth $1.4 billion, according to an investor presentation lodged with the ASX last month."We were the solicitors for Consumer Action when Nicole Rich first wrote her paper on penalty fees [in 2004]," said Slade, "and we thought we had a case then, but it took IMF and Financial Redress to come along with an online sign-up before we could see how it could be done."The Federal Court was chosen by Maurice Blackburn as the place to file this case because it has the greatest commitment to processing these kind of claims quickly, said Slade."There was discussion, but we decided that this court had the most appropriate procedures, and better developed commitment to class action claims."