A Senate committee has urged Immigration Minister Amanda Vanstone to scrap the proposed laws, which would see all unauthorised arrivals processed offshore.
Several government backbenchers have also expressed concern and are calling for a compromise to be reached.
However the government has moved a motion fast-tracking the passage of bills through the lower house, meaning debate on legislation - including the migration bill - will be cut short.
Immigration Parliamentary Secretary Andrew Robb said the changes will stop people seeking to use the country's immigration laws to make political statements.
"I think they do so in a very fair and satisfactory manner which certainly meets all of our international obligations and does take potential refugees and those seeking protection through internationally accepted processes," he said.
"I think we will work through this sensibly within our party and hopefully we'll see this legislation in place over the next day or two."