Senator Keneally, one of the winners among new Opposition Leader Anthony Albanese's frontbench appointments, quickly had to defend herself against verbal attacks from Mr Dutton, who said she had a record of not supporting tough border protection measures.

She said she supported boat turnbacks, offshore processing and regional resettlement but insisted they had to be done humanely.

Mr Dutton had been taking credit for stopping asylum-seeker boats with measures that had in fact been the work of now Prime Minister Scott Morrison, Senator Keneally said.

"Peter Dutton has in fact allowed people smugglers to evolve their business model from using boats to using planes," she said.

In the past four years, the number of people claiming asylum after arriving by plane had risen to more than 81,000.

Most were not refugees and, while their cases were less complicated than those of people who had arrived by boat, they were "languishing on bridging visas for two and three years".

"The blowout in bridging visas is extraordinary," Senator Keneally said.

A former NSW premier, she said that with a dedicated home affairs spokesperson, Labor would be able to "apply a blowtorch" to Mr Dutton's performance.

"That's what I intend to do."

Senator Keneally has in the past written about her misgivings over the key policies of boat turnbacks and offshore processing, though she did not exactly express opposition to them.

Mr Dutton nonetheless seized on her written columns in The Guardian from 2015 and 2017 as evidence there was "nobody less qualified in the Labor Party on border protection matters than Kristina Keneally".

"Look, it's something that I don't think she can explain, and Kristina Keneally really has to have a mea culpa at some point and come out and explain why she's had an epiphany that she believes now - credibly - she can occupy this portfolio."

Senator Keneally said yesterday: "I completely accept and endorse the approach of boat turnbacks, offshore processing and regional resettlement. But I believe we can secure our borders and still treat people humanely."

She said she would be pursuing the government over the Australian Border Force's troubled Cape Class patrol boats, as well as blowouts in visa processing and citizenship applications.

She said people were waiting for partner visas for two years. There were more than 230,000 people waiting on their citizenship applications.

She added Labor would be keeping a close eye on the national security architecture under the relatively new Home Affairs Department.