IT contractors who belong to trade unions can no longer be blacklisted for it by employers, under new government regulations.

Following evidence that firms in the construction sector were vetting workers based on their membership of trade unions, the practice has now been made unlawful, the Department for Business Innovation & Skills (BIS) has announced.

It is now an offence to sack or refuse to employ a suitable candidate based on any sort of industry blacklist, and individuals who are blacklisted can claim compensation against those who compile or distribute them, BIS reports.

Employment Relations Minister Lord Young said that refusing employment in this way was "underhand", and a "blight on people's lives".

"I am confident that this new piece of legislation will bring to an end the disreputable practice of blacklisting once and for all," Lord Young added.

The Union of Construction, Allied Trades and Technicians (UCATT) disagrees however.

By limiting the law to "trade union activities" the government have effectively "given the green light" to blacklisting for other reasons, such as unofficial work stoppages due to safety fears, said Alan Ritchie, general secretary of UCATT.