Great Train Robber Ronnie Biggs has had his appeal against his 30-year jail sentence dismissed at the High Court.
Ronnie Biggs returned to the UK in May 2001
But his son Michael said his 74-year-old father would fight on and take his case to the European Court of Human Rights.
A judge said on Thursday the appeal was "hopeless" and "completely misconceived".
Biggs, 74, has been held in the hospital wing of Belmarsh prison, south-east London, since he returned to the UK two years ago.
He claims his sentence was harsh compared to the jail terms given to his co-defendants in the mail train heist case in 1963.
Biggs was one of a gang that robbed a Glasgow-to-London mail train escaping with £2.6m.
He was convicted but had served only two years of his sentence when he escaped from Wandsworth Prison.
Biggs had hoped the Criminal Cases Review Commission would refer his sentence back to the Court of Appeal.
But the Commission refused and Biggs' challenge against this decision in the High Court has now failed.
No-one appeared to represent Biggs on Thursday and his case was dismissed by Mr Justice Jackson and Mr Justice Silber.
But his son Michael said his father's lawyers were now drafting an application to the European Court of Human Rights.
"The simple fact is that I can't pay for this battle."
He said there had been a delay of more than a year with his father's legal aid application with no decision yet made by the Legal Aid Board.
'No threat to society'
"Paedophiles get it straight away, murderers get it straight away but, for
some reason, Ronnie Biggs doesn't," he said.
"We will now go to the European Court of Human Rights where we might have a better chance."
He said his father, who cannot read or speak and has to be fed through a tube, posed no threat to society.
"He shouldn't be in Belmarsh where it's costing the taxpayer about £150,000 a year to keep him. This is a travesty of justice."
One of Biggs' complaints is that his co-defendants were given jail terms of between six years and 25 years.
Bruce Reynolds served seven years of his 25-year sentence.