Geoff Lloyd, director of HM Revenue & Customs central compliance directorate, was clear when he spoke to an audience of advisers and finance directors last week that there was ‘no single definition’ of tax avoidance.

But the tax authorities do want to wipe out avoidance, whether it be definable or not. HMRC director general Dave Hartnett announced in October that the department wanted to make avoidance ‘not worthwhile’. The latest plan is some combination of the carrot and the stick.

‘We want to leverage the benefits to advisers of reducing risk for their clients,’ Lloyd said, implying that the department would reward advisers who steer clear of avoidance.

What that could mean is unclear. Advisers who do things that are legal can hardly be punished or attract negative consequences, however much HMRC dislikes it, a point picked up by Bill Dodwell of Deloitte. ‘I would love to hear how that is possible under the law,’ he said.

Richard Murphy, the anti-avoidance campaigner, has speculated that that might mean advisers involved in avoidance would see their clients investigated more regularly.

Dodwell thinks the real problems lie with back-street advisers, who work in the hinterland of tax, and anyone who works within the law cannot be unfairly treated.

The department’s other strategy seems to be to punish those who make mistakes, perhaps with fines for big businesses.

‘People don’t always get schemes right. We think it may represent negligence and should be treated as such,’ Lloyd said.