Liberal Democrat chief secretary to the Treasury Danny Alexander has announced a £900 million crackdown on tax avoidance and evasion, which may mean IT contractors find themselves under greater pressure to meet IR35 obligations.

The measure is part of plans to raise an extra £7 billion per year from 2014 to 2015, with the extra funding to be partly used to create a new team of HM Revenue and Customs investigators.

Additionally, the cash will be used to create bespoke teams to deal with cybercriminals and invest in anti-smuggling technology.

A spokesperson for the Public and Commercial Services Union said an estimated £120 billion of tax goes uncollected every year due to HMRC's lack of resources.

"It makes absolutely no sense to be cutting jobs in the department that is best placed to get in much needed revenue to help the economy get back on its feet," he added.