Several religious leaders have been arrested while staging a sit-in protest inside the Geelong offices of a federal Labor frontbencher over the party's stance on children in immigration detention centres.

Police arrested the protesters - from Christian groups including the Salvation Army and the Uniting, Baptist and Catholic churches - on Monday night after when they refused to leave the electorate office of Shadow Immigration Minister and Corio MP Richard Marles.

Police watch the "prayer sit-in" inside the Geelong offices of Shadow Immigration Minister Richard Marles. Credit:Love Makes A Way Facebook page

A police spokeswoman confirmed that seven people had been taken into custody and charged with trespass. All were bailed to face the Geelong Magistrates' Court on December 11, she said.

The group of seven had been holding a "prayer sit-in" inside the office, saying they would not leave until gaining a public commitment from Mr Marles to "end the bipartisan brutality" and demand the release of all children and families from immigration detention centres.