HM Revenue and Customs inspectors are picking on specialist trades in home improvement where they think tax evasion is rife.

Construction workers who are dodging tax have been told to pay up ahead of the planned crackdown later this year.

It follows a campaign declared a success against plumbers last year. Nearly 600 people came forward to “notify” HMRC of their intention to declare unpaid tax.

So far, nearly £4m has been paid and 10 plumbers have been arrested, with more arrests planned.

In addition, more than 1,000 civil cases have been prepared.

Inspectors are vowing to pull together all available information to track down tradespeople that have not paid full tax, threatening big penalties and criminal prosecutions.

Marian Wilson, of HMRC’s Risk and Intelligence, said: “Using new technology, we have been able to analyse returns to HMRC covering a range of taxes and to cross-reference these with other information to build a picture of where we believe we have taxpayers with missing returns.

“We are offering all the people targeted the opportunity to come forward. Penalties will be higher if we come and find people after the opportunity. A criminal investigation may also result. I therefore urge them to disclose unpaid tax voluntarily.”

Inspectors will put together a jigsaw of information in order to find out where traders may not have been declaring income and not paying tax as a result.

Gary Ashford, of the Chartered Institute of Taxation, said: “These campaigns are a real statement of intent from the government.”

The coalition aims to save £7bn over this Parliament by tackling tax avoidance, evasion and fraud.