Trade unionists will be delighted that Blacklist Support Group allegations of police involvement in compiling victimisation lists are finally to be investigated.
The successful appeal by Christian Khan solicitors to the Independent Police Complaints Commission is a cause for celebration, but this is no time for complacency.
Christian Khan partner Sarah McSherry's insistence that the Metropolitan Police Directorate of Professional Standards should not be involved in investigating the complaint is a necessary safeguard.
Our parliamentary elite refused for decades to accept the possibility that trade unionists in the construction industry and elsewhere were being systematically denied the right to work.
Whether this was because of naivety or a reluctance to rock the boat and risk alienating a major source of political party funding is open to discussion.
Similarly, it was only in the wake of the News of the World phone-hacking scandal and related skulduggery that MPs would accept openly that some police officers were prepared to sell their integrity to a private company intent on law breaking to boost corporate profits.
None of this is new to building workers who still remember the government-judiciary-police-employers conspiracy to stitch up trade unionists in the wake of the successful construction industry pay strikes in 1972.
Police said during the strike that picketing had been effective but peaceful and it was only months later that a case was put together in Shrewsbury against two dozen leading activists, including Des Warren, Ricky Tomlinson and John McKinsie Jones, who were all jailed on trumped-up conspiracy charges.
The Official Shrewsbury 24 Campaign is still fighting to overturn this injustice and to quash the guilty verdicts, seeking a posthumous pardon for Des Warren who served every minute of a three-year sentence and contracted Parkinson's during his ordeal.
Shrewsbury marked the most visible and scandalous example of employer-state collusion to deny basic human rights to building workers, but it was not a one-off.
Consulting Association chief executive Ian Kerr, who was instrumental in drawing up a blacklist and sharing its contents with most major construction companies, came clean in 2008.
Kerr told The Times then that he and eight building industry directors had attended a meeting addressed by a National Extremism Tactical Co-ordination Unit "key officer."
Had Kerr not died in December 2012, just a fortnight after briefing the House of Commons Scottish home affairs committee on blacklisting, he would have been an important witness in a High Court compensation case against construction employer Robert McAlpine.
Labour movement campaigners have often been dismissed as fantasists for their claims of being spied on by secret police agents.
Evidence emerging in recent days indicates that the Consulting Association blacklist also contains the names of over 200 environmental activists, as well as detailed reports from anti-racism demonstrations, which hints strongly at police or intelligence services involvement.
While the Murdoch media role in corrupting some police officers for its own sordid purposes appears to involve the proverbial "few rotten apples," blacklisting of trade unionists and political activists seems more widespread and systematic.
It is good that Operation Herne will investigate blacklisting claims as part of its probe into the Special Demonstration Squad section of Special Branch, but more is required.
Nothing short of a full-scale public inquiry can shed a spotlight on this scandal and offer belated justice to thousands of innocent victims of state repression.