There is "no clear basis on which to require additional capital holdings," Westpac insisted yesterday in its second round submission to the Financial System Inquiry.This concept, affecting big banks, is the centrepiece of David Murray's panel's interim report and follow up consultations. It is one that grates with the sector."Any further policy options to address the issue of 'too big to fail' need to be justified on the basis that there is an additional, unknown vulnerability in Australia's financial system beyond that which is contemplated in existing stability settings," Westpac said."There is no clear evidence of this."Westpac said: "there is no evidence of market-based pressure from international investors for Australia to implement idiosyncratic measures to further address 'too big to fail'."Australia is not disadvantaged by its existing stability settings and approach to TBTF as an importer of capital," the bank said.