The Treasury is currently in the process of drawing up new legislation to tighten the tax evasion laws, the BBC reveals.
Existing law means it needs to be proven that an individual had criminal intent before a conviction is made against them.
A new law would provide “a fast-track route to criminal prosecutions” and would “inevitably lead to a jump in successful prosecutions and more jail time”, said Michael Avient, tax partner at national accountancy group, UHY Hacker Young.
“HMRC had proposed a significant lowering of the barrier to achieving a prosecution against offshore bank account holders by removing this burden of proof,” he added.
The HSBC scandal emerged after a former IT worker, Herve Falciani, leaked documents to the French authorities in 2010.
It was announced on Wednesday that HMRC would widen its enquiries into tax evasion and would corroborate with other UK authorities, including the Serious Fraud Office.
“It was expected that the introduction of a new tax evasion law was going to be brought forward in the Autumn Statement but it was quietly dropped,” said Avient. “We are opposed to this measure as it may lead to prosecutions of people who are simply negligent or forgetful.”