Angry protesters descended on union-busting firm Laing O'Rourke on Saturday following a tragic death on a London construction site.

Blacklist Support Group (BSG) activists furious at its refusal to allow union access to its projects demonstrated outside the company's multimillion-pound Alder Hey Hospital site in Liverpool.

Electrician and BSG chairman Steve Acheson said the firm was continuing to bar workers despite facing a major High Court case for using the notorious Consulting Association blacklist to weed out trade unionists.

Laing and seven other big construction contractors are in court on November 29 after using the 3,200-name list to keep individuals off its projects.

It has since apologised and offered a meagre "compensation" scheme that those affected have rejected as a "publicity stunt."

But Mr Acheson said: "They show their true colours every day by their anti-union actions on building sites across the UK.

"They appear to be pathologically predisposed to victimise workers prepared to stand up for basic rights such as safe conditions or wages.

"Until blacklisted workers are able to gain long-term employment on major projects, everything else is just window dressing and we will continue to hound these wretches."

BSG is demanding the right to employment for those barred, compensation for lost earnings, and a full independent inquiry into blacklisting.

Saturday's protest took place days after a man died on another Laing project - London's Francis Crick Institute - where union officials have been barred by company bosses.

Police and the Health and Safety Executive are probing Wednesday's incident that saw the unnamed victim crushed to death by a concrete stairwell.

It is one of several deadly incidents at Laing projects.

The firm paid out £150,000 in 2009 following the death of Matthew Gilbert and serious injury to Parminder Singh who were hit by a falling concrete slab at Heathrow.

A separate £135,000 fine followed safety breaches that saw steelworker Kieron Deeney plunge 10 metres to his death in east London.

Unite union assistant general secretary Gail Cartmail demanded that the firm reverse its "bizarre" site ban on reps.

"There is no place for anti-trade union behaviour in an industry where we should be working together in the interests of safety," she said.