Labor appears no closer to lining up an extra two weeks of federal parliament to deal with the recommendations of the banking royal commission against the government's will.
Prime Minister Scott Morrison is also pushing back against the opposition's call for new laws to jail shonky bankers, saying the changes are reckless and risk creating more problems.
In the wake of the damning royal commission, Labor wants to significantly increase penalties against financial institutions who break the law before the May election.
The opposition on Wednesday hoped to introduce amendments into the Senate to overhaul existing laws, lifting jail time for corporate crimes from 10 to 15 years and more than doubling the proposed cap on financial penalties to $525 million.
"Only Labor will clean up the banks. We fought for this royal commission and we will finish the job," Labor leader Bill Shorten said.
But Centre Alliance senators sided with the government to prevent the changes being brought on for debate, ahead of other planned discussions.
Mr Morrison has warned against them.
"Bill Shorten has a very reckless opportunistic approach to these serious matters," Mr Morrison told reporters in Canberra.
"He says we should recklessly prepare legislation in response to 40 recommendations without having the opportunity to consider unintended consequences."
The discussion comes as Labor's efforts to tee up two extra sitting weeks of parliament look set to fail because of independent Queensland MP Bob Katter.
The opposition must win over all seven crossbenchers to achieve the 76 votes it needs in the House of Representatives to add the extra sitting days in March.
Mr Katter has declared he does not want parliament extended, despite supporting the idea a day earlier.
Instead, he is calling for immediate legislative and regulatory changes.
"I don't want any more looking into it or further inquiries or extending parliament, I just want it to happen," Mr Katter said.
The opposition's chief tactician, Tony Burke, on Tuesday said Labor would try to get the extra days once it had 76 votes.
"So we're continuing the discussions," he told reporters.
But Treasurer Josh Frydenberg said Labor hasn't even provided its own response to banking royal commissioner Kenneth Hayne's 76 recommendations, except for embracing them "in principle".
"We are taking action - the Labor Party can't even be bothered with a response," he told parliament.