Vicky Pryce was presented with a "fait accompli" by Chris Huhne that she must accept his speeding points, her brother told a court today.
George Courmouzis, a Greek businessman, told his sister's trial that she was irritated and upset that he had nominated her as the driver and reacted as someone who had "done something beyond her will".
He said he had between three and five discussions with his younger sister over the matter in 2003, soon after it happened, at a time when he had a house in the Notting Hill area of London.
"I remember irritation...over the fact that Vicky was forced by Chris to take speeding points because he had reached his limit but mostly irritation about the manner in which she was presented with no option but to take the points because she was summoned," he told the jury.
"She was presented with a fait accompli."
Pryce, 60, an economist from Crescent Grove in Clapham, south London, denies a charge of perverting the course of justice.
Huhne, her ex-husband and a former Cabinet member, has admitted the same charge and resigned last month as the Lib-Dem MP for Eastleigh.
She is claiming a defence of marital coercion, saying he forced her to take the points on her behalf.
Courmouzis, who works in sports marketing and is godfather to one of Pryce's children, told Southwark Crown Court in London that Pryce's irritation had grown after Huhne was banned soon afterwards after being caught speeding again and it became a "point of contention between them".
"It was frustration I guess, on the part of Vicky, and it was a point of contention between them, concerning driving habits, concerning the fact that she was forced to do something beyond her will and his behaviour was not remedied by it," he said.
Courmouzis was asked by prosecutor Andrew Edis QC why she did not go to the police if she was upset by it.
"That carried conditions that were not exactly favourable to the family, he said.
Courmouzis, who was not called as a witness in Pryce's first trial, said that he spoke to Chris Huhne about his sister taking his points for him in 2003.
He said that the former environment secretary brushed him off and said "it doesn't matter".
"He dismissed it," Courmouzis said.
"I think he was very uncomfortable discussing it."
Edis asked: "He seemed quite relaxed about the fact you knew all about it, did he?"
Courmouzis said that was true.
Edis summed up his case this afternoon, urging the jury of five women and seven men not to be swayed by sympathy for Pryce.
He described her as a capable, manipulative and intelligent woman who acted of her own free will.
Despite having to put her own successful career as a Government economist behind his political one, he said, she still had "a real interest in his career".
If Huhne was elected to Parliament he would be at home more than he was as an MEP, he suggested.
"Actually, it is just better for the family if he keeps his licence," he said.
"If that's her thought process then it would not be his pressure that was the only reason why she took the points.
"She had other reasons of her own."
This situation changed when Huhne left her for his adviser Carina Trimingham shortly after the 2010 General Election, he said, sparking her decision to leak the story to the press.