A former chairman of the Scottish Child Abuse Inquiry is suing the Scottish Government for £500,000 in loss of earnings and damage to her reputation following her departure from the role last year.

According to papers lodged at the Court of Session, Susan O’Brien, QC, is says she was forced out after attempting to defend the inquiry’s independence from Government.

She was asked to quit after a psychologist working with the inquiry objected to comments she had allegedly made in a private meeting. These were put in the public domain by Education Secretary John Swinney, who said that, if they had become known to survivors, they would have made her position “untenable”.

However, the court papers say Ms O’Brien “considered that she had a duty to inform the public that the inquiry’s independence was being actively undermined by the defenders[the Scottish Government]”.

They add: “It was an implied term of her contract that as chair she would defend the independence of the inquiry from any interference and control by government.”

She was backed at the time by Glenn Houston, who is still working on the Inquiry team, and Professor Michael Lamb, who also resigned his position on the grounds of Government interference.

At Parliament House in Edinburgh, yesterday, Lady Smith insisted the SCAI would operate free of interference. She said: “Had I any concerns about its ability to do so, I would not have accepted this appointment.”

A Scottish Government spokeswoman said: “Ministers have acted appropriately at all times and continue to be committed to the independence of the inquiry.”