The world's largest banks are into the homestretch of a long campaign to convince politicians and regulators that planned changes to their capital requirements will suffocate the industry and imperil lending and growth. All that lobbying is paying off when it counts.

The Basel Committee on Banking Supervision will hold three crucial meetings in the next two weeks as it races to wrap up the post-crisis capital framework by the end of the year. The banks warn that proposed changes in how they assess risk would send capital requirements spiraling, and key policy makers from Europe to Japan are heeding their message.

The banks' lobbying success was on display this week. Andreas Dombret said the Bundesbank, where he's in charge of financial supervision, had considered the industry's arguments and concluded that “there is a need to recalibrate” the Basel proposals. The European Union's top two officials then insisted in a position paper before the Group of 20 summit Sept. 4-5 that the Basel Committee stick to its promise not to increase capital requirements significantly as it refines risk measurement.