This 26 July 2016 video from Britain says about itself:
Darrell’s story: construction worker victim of construction blacklist scandal
Darrell Crapper, a former steel erector/rigger, and his wife, Bridget Crapper, talk about how blacklisting affected their finances. Unite the Union waged a five-year fight against the construction firms that were part of the conspiracy, resulting in more than £10 million in compensation secured for 256 workers who were victims of the blacklist.
By Trevor Johnson in Britain:
UK police colluded in blacklisting of workers
22 March 2019
The release of a previously secret report exposes how the police collaborated with big companies to blacklist workers.
The report was marked on its front cover “[Police] Commissioner only”. While the released version is heavily redacted, it shows that police agencies including the Special Branch secret service and its infiltration unit, the Special Demonstration Squad (SDS), colluded with blacklisting agencies such as the Consulting Association (CA), a secretive body funded by employers, and its predecessor the Economic League (EL).
Blacklisting was only made illegal at the end of the Labour government of Prime Minister Gordon Brown in 2009, and even then only as a civil offence, not a criminal offence.
Big businesses used the CA and the secret police to spy on workers and hired and fired them based on the information collected—often lies and distortions. The blacklisted workers and their families were condemned to a life of poverty and hardship.
One worker was falsely described by the police as having a link to terrorism, ensuring he was refused employment. Showing how the EL worked in 1978, the case was uncovered as a result of a senior police officer who was related to the blacklisted worker and intervened on his behalf.
An active trade unionist, the worker had applied for a job making training videos for a company with links to the construction firms. The company asked the EL for information on him, causing the EL to go to the police “due to the perceived risk of involvement in education.”
“The receiving officer’s initial inquiries revealed a potential link to [redacted] which in his opinion had not been resolved satisfactorily… he returned to EL asking for any further information, stressing the matter’s importance due to the possible link to terrorism. This was recorded as fact by the EL representative.”
The EL reported back to the employer and the worker was turned down.
The Economic League was wound up in 1993, before blacklisting was made illegal. It had accumulated files on around 22,000 people. The CA was founded in the same year by Ian Kerr, described as a “key” figure in the EL by its director.
The CA was raided by the Office of the Information Commissioner in February 2009. Although only 15 percent of CA’s material was confiscated by the IC, it was enough to prove that it was illegally keeping a blacklist on more than 3,000 workers based on their trade union membership, political views and any raising of health and safety concerns.
It got information from the police agencies, including the Special Branch and the Special Demonstration Squad (SDS).
The CA got its funding from companies, which paid fees of several thousand pounds per year, as well as paying for each file they accessed. The list of more than 40 companies includes all the major construction firms.
The report states, “Police, including Special Branches and the Security Services supplied information to the blacklist funded by the country’s major construction firms…”
The Metropolitan Police Special Branch Industrial Unit spied on trade unionists “from teaching to the docks, attending conferences, and protests personally, and also developing well placed confidential contacts.”
The report makes clear that police are still sharing information about workers with big businesses and other bodies by means of the Industrial Liaison Section of the National Domestic Extremism Unit.
Mark Jenner was an undercover police spy from 1995 to 2000, who entered a five-year relationship with an innocent, law-abiding woman as part of his cover story. He posed as a construction worker and joined UCATT. He also infiltrated the Colin Roach Centre, which was involved in numerous industrial and union disputes, particularly in the construction industry.
The centre was associated with the Building Workers Group (BWG) and hosted some of its meetings. Jenner was also a member of the BWG.
His activities in UCATT, the BWG and the Colin Roach Centre gave Jenner “ample opportunity” to spy on workers involved in disputes. He provided information on more than 300 people, at least 16 of whom appeared in the illegal blacklist.
On March 12, 2015, former SDS police spy-turned-whistleblower Peter Francis made a statement on his own and Jenner’s activities targeting trade unions, saying, “[H]ere in this supposed home of UK democracy, please let me state very clearly that Mark Jenner was 100 percent one of my fellow undercover SDS Police Officers deployed alongside me in the 1990s.
“Jenner, who has now been very publicly exposed, should be forced to appear in person at the public inquiry to account for his spying on, amongst numerous other political protesters, the totally law-abiding construction union UCATT members whose only ‘crimes’ were being union members.
“I would also like take this opportunity to unreservedly apologise to all the union members I personally spied upon and reported back on whilst deployed undercover in the SDS.”
The targets of his spying included “not only [those] engaged in working in the construction industry but also those in the National Union of Students (NUS), National Union of Teachers (NUT), Communication Workers Union (CWU), UNISON and the Fire Brigades Union (FBU).”
After becoming a whistleblower, Francis was threatened with prosecution under the Official Secrets Act.
Trade unionist Michael Anderson “discovered that on his file there was a note saying that the union Amicus had recommended he not be employed. Several of those who have received their files have raised concerns that information appears to have come from union officials. Anderson said: ‘I have written and asked Unite the union to conduct an independent inquiry into who “of Amicus” was responsible for supplying information that I was “not recommended” by my own trade union. I have received no reply. I have also asked how other privileged detailed information about which members attended union branch meetings and discussions held at branch fell into the hands of The Consulting Association. I have received no plausible reply.’” 
The building industry has the worst record of all for fatalities at work, with 38 deaths in 2017-18. The report on blacklisting sheds some light on the methods by which such dangerous conditions were imposed, but a lot more is yet to come.
The official papers on the prosecution of the Shrewsbury building worker pickets in 1972 and how they were railroaded into prison have yet to be released. One of the pickets, Des Warren, who became a member of the Workers Revolutionary Party, then the British section of the International Committee of the Fourth International, was kept drugged while in prison and suffered permanent damage to his health and an early death.
His son Andy Warren has stated, “My dad argued that he was not a criminal, he was a political prisoner. He spent eight and a half months in solitary confinement. Both him and Ricky Tomlinson went on hunger strikes in protest at the way that the prison authorities treated them. My dad endured three hunger strikes, the longest lasting 22 days…
“When my dad was finally released and came home he was never the same… My dad never worked again. Every employer in the country blacklisted him. After a time his health began to fail due to the treatment that he had endured in prison, particularly the drugs.” 
Des Warren died in 2004 aged just 66.
 The construction industry blacklist: how the Economic League lived on, Winter 2009/10, by Phil Chamberlain
 My Dad, Des Warren, by Andy Warren