Labor has faced savage criticism for backing new laws to force migrants to wait four years before they can get the dole.
Legislation cleared federal parliament on Monday night, with the Greens attacking the opposition's deal to support the coalition government's push to extend the wait time for Newstart from three to four years for migrants.
"This bill will create an underclass of migrants in our community and will result in second-class citizens who will now have to wait longer to get the support they need," Greens senator Rachel Siewert said.
She said Labor had enough crossbench support to sink the bill, but had eyed off $1.3 billion in budget savings they could snaffle if elected at the next federal poll.
The government had initially wanted all welfare payments to have a four-year wait time, but agreed to shorter periods for a raft of payments after negotiating with Labor.
Under the major parties' deal, the wait for carer payments, parental leave pay, as well as dad and partner pay will be extended to two years.
The changes will result in a one year wait for a carer allowance and family tax benefit part A.
Wait times will not apply to single parent migrant families or those with one income earner.
Independent senator Fraser Anning wanted to remove an exemption for refugees which he said would target the "main class of welfare seekers who wash up on our shores".
"The sad truth is that freely available welfare is the pull factor in drawing fake refugees to our shores," Senator Anning told parliament.
But government minister Zed Seselja said Senator Anning's amendments would remove important protections for vulnerable refugees and their families.
"It is longstanding policy that refugees and their families are exempt from all waiting period for welfare payments," Senator Seselja said.
