At time of writing, the campaign had raised £21,110, having previously been stalled around the £18,000 mark for around a fortnight. One of the most recent donations, which comes from an anonymous source, is for £3,000.
Hayes became the first person to be found guilty of offences related to manipulating Libor in the UK in August last year. He was initially sentenced to 14 years in prison, but this was subsequently reduced to 11 years on appeal.
Hayes was told in March that he must pay £878,806 under a confiscation order and, during the hearing, he described to the court how he had lost nearly everything trading in attempt to raise money for his initial legal fees.
A statement posted on the fundraising website on Sunday, attributed to the Tom Hayes Support Group, reads:
We have today passed the £20k mark and the team has started work. Tom is now back in HMP Lowdham Grange and is thrilled with the support he is getting in the House of Lords.
Tom and his family thank you all for making this possible. Please continue to tell your family, friends and colleagues about our fundraising efforts. We have a way to go yet, but we are absolutely determined to right this wrong.
Hayes was moved to Belmarsh prison in south-east London for his confiscation hearing, which took place at the Old Bailey.
In an impassioned speech last month, Conservative life peer Lord James told the House of Lords that the Libor scandal was an "urgent matter that should be getting very close attention of your Lordships' house".