HM Revenue & Customs will only receive 10% penalties on outstanding amounts if they come clean before the cut-off date.

Sparks found owing tax after the deadline will be hit with penalties of up to 100% and face criminal investigation in the worst cases.

Marian Wilson, head of HMRC Campaigns, said: “Electricians who think they owe tax should get in touch and get their tax affairs in order, easily, and on the best terms.

”We are gathering information from a wide range of sources, including online advertising, industry bodies, trade directories, professional ‘electrical safety’ certificates, trade suppliers and tax records.

“Our sophisticated software allows us to use this information to find people who should come forward and use the Electricians Tax Safe Plan.”

The campaign follows a similar initiative targeting plumbers and heating engineers.

Fourteen plumbers have been arrested so far, and one was jailed for 12 months in March for evading £91,000 of tax and national insurance.