Kevin Lay had failed to submit Self Assessment returns or complete VAT returns since setting up his plumbing and maintenance business in 1997.

He also ignored an HMRC initiative to disclose any unpaid tax he owed.

John Cooper, Assistant Director Criminal Investigation for HMRC, said: “In 2011, HMRC ran a campaign giving plumbers like Kevin Lay the opportunity to disclose any unpaid tax they owed.

“He chose not to take this opportunity, and instead found himself subject to criminal proceedings.”

At Reading Crown Court Lay of Ascot was jailed for two years.

He had admitted two counts of cheating the public revenue at an earlier hearing. He was sentenced for two years for each count to run concurrently.

Her Honour Judge Morris said: “This was not a sophisticated fraud…but fraudulent from the outset.

“You knew you should have paid tax but persistently avoided doing so. Such a fraudulent enterprise over such a long period of time must expect an immediate custodial sentence because the impact on the public purse is significant.”

Simon York, HMRC Director of Risk and Intelligence Services, said: “We want people targeted by our campaigns to come forward, use the opportunity to put the record straight, and pay the tax due on the best possible terms. It really is better to come to us before HMRC finds you.”

Plumbers who have come forward in response to the Plumbers Tax Safe Plan (PTSP) have already paid over £4m in outstanding tax.

A further £2.4m has also been recovered from follow-up enquiries.