The mother of computer hacker Gary McKinnon fears that Nick Clegg is now "washing his hands" of her son's fight against extradition to the US.
The Deputy Prime Minister has been one of Asperger's sufferer Mr McKinnon's staunchest supporters in the campaign for him to be tried in the UK - where all his crimes were committed.
However, Janis Sharp says that since coming into power, the Lib Dem leader has refused a personal request to meet her, stating it "would be better all round" if they did not discuss the ongoing case.
Mr Clegg said the decision was out of his hands and now that of the Home Secretary, Theresa May.
Mrs Sharp told the Daily Mail: "I wanted to raise my concerns with Mr Clegg as it is right and proper and by no means unreasonable in the horrific circumstances to which Gary and I are being subjected.
"I'm now afraid that he might be attempting to wash his hands of Gary and perhaps sees Gary as a thorn in his side.
"I so hope this isn't true as I trusted Nick Clegg to the core - I really believed in him.
"The Lib Dems used my son's case pre-election and as far as I am concerned it was 100% commitment to him. How can we have any trust in politicians when they behave like this?"
Mr McKinnon, 45, has spent the past seven years facing the threat of extradition to the US after he hacked into top secret military computers in 2002.
American officials have demanded that he is tried in the States despite expert opinions obtained by Mr McKinnon's legal team warning that his mental condition could lead him to commit suicide.