Nick Clegg today said he was "confident" Liberal Democrats would back the coalition's controversial health reforms ahead of a potential vote calling on the plans to be dropped.
Voting is due to close shortly on whether the party should take an emergency motion on the final day of its spring conference tomorrow demanding the withdrawal of the Health and Social Care Bill.
A rival option put forward by Baroness Williams, who initially opposed the proposals, calls on Lib Dems to support the changes.
During a visit to the Siemens factory in Newcastle today Clegg said he believed members would be "comforted" by the raft of amendments made to the original Bill.
He said: "I think it is quite right that people have a look at it. My own view is that when people look at what we have done rather than what we are alleged to have done, because many of the critics I speak to about the Bill when I ask them if they have read the health Bill they say they haven't, I think there is a big gap between what people think the Bill is going to do and what it actually says, I think when people actually see that they will be quite comforted."
He added: "When they are confronted with a choice between trusting Shirley Williams's judgment and trusting (Shadow Health Secretary) Andy Burnham's opportunism, I believe they will back Shirley Williams and back the changes that she and other Liberal Democrat colleagues have introduced to the Bill."
The legislation was "paused" after the party's spring conference last year amid a furious backlash. It has since been amended more than 1,000 times but many prominent health organisations remain fiercely opposed to the plans.
Asked what would happen if the party did vote to kill the Bill tomorrow, Clegg said: "I don't want to get into what if, what if. Let's let party members debate this because, quite rightly, party members instructed me and Shirley Williams and others to make significant changes, particularly in 13 areas which were set out in a tablet of stone in our conference a year ago.
"We have gone away and made those changes and I think it is quite right now that party members have got an opportunity to examine whether those changes have been made.
"I believe they have been, Shirley Williams believes they have been."
The Lib Dem leader accused the unions of "sabre rattling" after claims today pursing the plans was "electoral suicide".
He insisted if he thought the Bill was going to destroy the NHS "it wouldn't have seen the light of day".