Former 39 Essex Street QC Rohan Pershad has been jailed for three and a half years after being found guilty of tax fraud worth more than £600,000.

The sentencing today (26 February) in court room five of Blackfriars Crown Court comes after clinical negligence specialist Pershad took silk just two years ago.

Investigators at HM Revenue and Customs (HMRC) found that Pershad failed to declare or pay £627,839 of VAT over a period of 12 years, instead spending the cash on luxury homes and private school fees for his children.

He was found guilty on 11 February after being initially charged last July. He denied the charge of VAT fraud.

Pershad was deregistered for VAT by HMRC in February 2000 following a history of failure to submit tax returns or informing HMRC of a change of address. This stopped him legally trading above the VAT threshold, though between 2001 and 2008, he continued to use his invalid VAT number on invoices.

Pershad has confirmed he intends to appeal his conviction, which he describes as "wrong and unsafe".

In a statement, he said: "I have not acted dishonestly in relation to the payment of VAT and I will be seeking to have my conviction overturned in the Court of Appeal. There have been a number of inaccurate and misleading comments made publicly since my conviction. I will seek to correct them at the appropriate time.

"I am very grateful to all the many people that have stood by me at what has been a deeply distressing time – most of all for my family. I am not a dishonest man. I have never sought to defraud or cheat anyone. I will continue to fight to clear my name."

Keri Ashworth-Beaumont, specialist prosecutor from the Crown Prosecution Service central fraud division, said: "By convicting him today, the jury has concluded that Pershad was acting dishonestly and his failure to pay was not simply an error or mistake.

"He claimed that his chambers had given the impression that payment of his VAT had been taken care of, but the jury clearly rejected that assertion. Pershad always admitted that he understood the law and the responsibility for meeting his obligations rested on him alone.

"The message is clear; paying tax is not an optional extra, in any area of working life and withholding tax dishonestly may lead to prosecution," said Ashworth-Beaumont.

39 Essex Street declined to comment, but said in a statement issued on 11 February said: "It is and always has been clear that all members of these Chambers, in common with all other self-employed barristers, are personally responsible to account to, and pay, HMRC for VAT received, and for income tax, and it is right that tax evasion should be appropriately punished when proved."

Andrew Marshall of 18 Red Lion Court led for the prosecution, while 9-12 Bell Yard Chambers head Mukul Chawla QC defended Pershad, with additional advice coming from Kingsley Napley partner Angus McBride.

Donald Toon, HMRC director of criminal investigation, said: "Pershad's 12 year history of tax evasion was blatant theft from the public purse. He thought he was above the law, but someone in his profession should have known better than to try to cheat the system, as HMRC will not stand by while criminals try to cheat the taxpayer.

"Declaring and paying VAT that is due is a legal requirement – not a lifestyle choice – so we are pleased that justice has been served and he will spend the next three and half years behind bars."