James Bogle, who's also part of Catholic Union, was speaking after barristers went on strike in support of criminal defence solicitors, who've seen a nine per cent pay drop since the government's reforms came into effect at the start of July.
It means some barristers will not be taking some Crown Court cases.
This government has reduced legal aid spending by a quarter, from £2bn a year to £1.5bn a year.
Mr Bogle told Premier's News Hour he had this message for the government: "If you're wanting to save money, this is not the way to do it.
"Apart from anything else, very little money will be saved by cutting legal aid anyway. But huge amounts of injustice will be done.
"Their reputation, and their whole life and that of their family, could well be on the line, and they're unable to get proper representation. They may find themselves convicted, even though they are innocent.
"Conversely, you may also find that people who have committed serious offences get off.
"The public thinks 'oh, well, barristers would go on strike wouldn't they, cause it's their pay packet'. But the fact is the publicly funded work is not the well-paid work at The Bar. It's the work done by people who are more interested in justice and helping those who are less well off and less fortunate."
Listen to Premier's Marcus Jones speaking to James Bogle on the News Hour:
A Ministry of Justice Spokesperson said: "The changes we are making to criminal legal aid are designed to deliver value for money to taxpayers and do not impact on the availability of high quality legal advice to those who need it most.
"Although we recognise that the transition will be challenging for lawyers, these changes will put the profession on a sustainable footing for the long term.
"We have already pledged that an independent review looking at the impact of the new arrangements will begin in July 2016."
