The Jesuit human rights activist said this week in Eureka Street magazine that the so-called Pacific Solution "throws into relief" the policy differences between the major political parties.
Labor is committed to abolishing the Pacific solution, while the Coalition would maintain it.
Fr Brennan pointed out that failed asylum seekers on Nauru have no right of appeal to any Australian court.
He commented: "The government does not make too much of this difference in public because it leads to the inference that decent Australian public servants are more likely to decide that a person is not a refugee if their deliberations are immune from scrutiny by any court or tribunal."
He added that Australian lawyers and so-called do gooders can be more readily kept out of Nauru.
On the issue of the other detention facility on Christmas Island, both parties would maintain it. Refugee advocates have criticised Labor for its failure to abolish Christmas Island.
Brennan said it is important to give credit where it's due. He praised the Howard government for increasing the the size of Australia's migration program, including the refugee and humanitarian component.
The impact of leaky asylum boats on the Federal Election (Eureka Street, 18/9/07)
LINKS (not necessarily endorsed by Church Resources)
Frank Brennan SJ (Wikipedia)
Pacific solution (Wikipedia)
Jesuit paper reminds Australia of responsibility to Nauru (CathNews, 14/07/05)