The on again-off again drift towards a commission of inquiry into the banking sector is set for a defining moment very soon. Queensland Nationals senator Barry O'Sullivan wants to set up an inquiry - with similar powers to a royal commission - into the banking, insurance, superannuation and financial services industry.Senator Williams has told Sky News the O'Sullivan Bill establishing a commission of inquiry into the banks has the numbers to pass the Senate.This is despite the contradictory noises being made by senior Liberals, including frontbencher Christopher Pyne, that the Nationals should discuss the issue at a partyroom meeting in Canberra next Monday, ahead of a joint meeting with Liberal colleagues on Tuesday, according to Sky News. "It'll pass through the senate, the senate numbers are there, regardless where I vote and I will be voting for it," he said."When it gets to the House, the numbers are very finely balanced, there's talk about a couple of Nats supporting it there."Fellow National, George Christensen, who is one of two in the House of Reps who will need to cross the floor to set up another banking inquiry, has set up a webpage, where he promises to "... put the spotlight onto systemic banking misconduct, put the facts on the table and back victims seeking redress from the unscrupulous actions of banks."The most likely way the Bill, and Act, will be taken off the agenda is if special interests are not included - for instance Queensland Nationals MP Llew O'Brien, who is on board with Christensen so long as the commission investigates discrimination against people with mental health issues.The former policeman, who was diagnosed with post-traumatic stress disorder, has a personal connection to the push, reports news.com.au.   However, debate on this bill won't start until the Senate votes on laws to enable same-sex marriage, expected late on Wednesday or Thursday.With the Prime Minister and other senior Liberals completely against the idea, a Royal Commission is out of the question, though, as one can only be set up by the executive of the Government of the day.The only sure thing is that the politicking and lobbying will continue until at least this time next week.