The 4 nations have, according to this report, lined up considerable support. However, they also face considerable opposition. Brazil is opposed by Mexico and Argentina. India is opposed by Pakistan. Japan is opposed by China, South Korea and North Korea. Germany is opposed by Italy. In fact, Italy, South Korea and Pakistan are lobbying for no change in the permanent Security Council seats at all. And, oh yeah, Egypt, Nigeria and South Africa are also waging separate campaigns for their own permanent seats, veto power and all.
The US says it would move forward if a "broad consensus" could be reached. This is apparently diplo-speak for "when hell freezes over, buddy". "Broad consensus" can be defined anyway you like it. 66% or 75% or 99.9% support, depending upon today's weather.
One amusing statement in the report:
The purpose of the change is to have the Council reflect the current balance of global power better than is the case with the original five permanent members (Britain, China, France, Russia and the United States) and 10 members elected to two-year terms.Well, if the purpose of the change is to "reflect the current balance of global power better", then there would be only one permanent seat on the Security Council, that held by the United States, with a hi-chair available for China to rattle its spoons.