Elaine Tappin spoke to reporters after she appeared before the Home Affairs Select Committee to talk about her husband Christopher Tappin's extradition.
She said he was very worried about him and his mental health.
Asked by a reporter if she had a message for President Obama and the US, Mrs Tappin said:
"Please be kind to him, don't treat him unjustly, and let him have his day in court quickly so he can come home to us."
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Shadow chancellor John McDonnell has backed a free vote for MPs on the issue.
Savers into the new scheme can expect rates as high as 4 per cent from some banks.
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