New Zealand's mutually-owned Co-operative Bank has launched an all-out attack on the Big Four Australian owned banks as Labour and Green MPs also criticised the banks' record annual profits.Co-operative bank opened a new branch in the capital Wellington with a marketing campaign focused on the multi-billion profits of the Australian banks, which were compared to crocodiles.Finance Minister Bill English cut the ribbon at the branch opening on Wednesday without formally endorsing the campaign, in which Co-operative Bank said crocodiles were being used as a metaphor for banks that were not able to change their focus from maximizing profits.Co-operative Bank had planned to serve barbeque 'Croc-dogs' to office workers at a park opposite the new branch on Wellington's Lambton Quay, but had to cancel because of bad weather.The branch windows featured a large crocodile and the phrase: "don't worry, your old bank can't get you here."The campaign included a crocodile mascot making guest appearances and crocodile-masked commuters leaving a trail of 'prize boxes' around Wellington.English told the bank staff and executives at the branch opening: "We wish you well, particularly in putting that competitive pressure on those bigger banks."English was questioned in Parliament on Tuesday by Green Co-Leader James Shaw about the Big Four banks' NZ$4.4 billion of profits over the just completed financial year and whether the Reserve Bank or Government would investigate or act to restrain those profits.English said competitive pressure was the best discipline and he encouraged those worried about the profits to join a New Zealand-owned bank. "It is heartening to see over recent years a growth of confidence in the New Zealand owned banks," English said."The digital world enables smaller, more focused, culturally stronger organisations to do better because digital breaks down scale and in a lot of respects it reduces transactional costs," he said.English fended off the questions in Parliament about bank profits being too high, saying "the one thing worse than profitable banks is unprofitable banks."Asked if the government planned to increase its investment in Kiwibank to enable it to compete more effectively with the foreign-owned banks, English said: " The best thing that New Zealanders can do to enable Kiwibank to compete more with the big Australian banks is to sign up to Kiwibank. In the end, that is what will make the most difference. The constraint on that bank is simply its ability to get customers. Of course, New Zealanders can also join the TSB Bank, or my favourite bank, SBS Bank, based on the Southland Building Society. "