Penny Allen and her fiance, Ismay Tremain, arrived gagged at the High Court for a hearing over an injunction preventing them from talking about her former marriage and the court proceedings about the children.
Ms Allen said, after removing her gag: "I have been silenced for five years.
"Since I met my husband he has manipulated the press and perpetrated libel and slander against me and now my husband to be."
Bitter custody fight
Last Thursday Ms Allen, 51, went on the run with McEwan's 13-year-old son after a court in Brittany, France, ruled that the boy should be returned to his father, who has sole custody over him, and his 15-year-old brother.
Mr McEwan won a temporary injunction banning disclosures from Ms Allen and her fiance, last Friday.
Earlier this year, the 51-year-old author won sole custody rights over the boys at Oxford County Court.
The pair's legal battle began after the break-up of their 13-year-old marriage in 1995.
Originally they shared custody, but the arrangement broke down when Ms Allen, a spiritual healer and therapist, moved to Brittany.
'The Destruction of Penny'
Outside court, Mr Tremain said he had changed his name by deed poll to Ian Russell McEwan to get around the injunction.
He carried a briefcase emblazoned with the Booker prize-winner's name and the words: "My next novel is entitled The Destruction of Penny Allen and Ismay Tremain."
Mr Tremain also wore a child's nappy and a rolled up paper in his mouth.
Mr McEwan was a prominent short story writer before going on to win prizes for books including Black Dogs.
His latest novel, Amsterdam, won the Booker Prize last year.
He married journalist Annalena McAfee in 1997 aftering divorcing Ms Allen.
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