South Australian MP Bernard Finnigan will learn on Wednesday if he will face trial on child pornography charges.

Last September, a magistrate committed the 39-year-old upper house MP to stand trial in the District court.

But Finnigan went to the Full Court of the Supreme Court in October, to challenge the committal.

He has pleaded not guilty to five aggravated counts of taking steps to obtain child pornography and one aggravated count of obtaining child pornography.

It's alleged the offences occurred at his home in the Adelaide suburb of Sefton Park between August 2010 and April 2011.

Chief Justice Chris Kourakis and Justices Tom Gray and Ann Vanstone will hand down their judgment on his challenge on Wednesday.

The MP, who served briefly as a minister in former premier Mike Rann's government, still sits in the South Australian parliament, which resumes next month.

He is now an independent after being expelled from the Labor party.

AAP mss/lhh/wa