However, Bruce Carr QC, who was asked by David Cameron to examine whether the law needed changing to prevent so-called leverage tactics, where managers are directly targeted as part of a protest, said there was no real evidence that unions had behaved badly.
The newly published Carr Review, which was commissioned in the wake of last year’s dispute at Grangemouth, said “there are some employers” who believe they were targeted by Unions such as Unite, which was accused of picketing the homes of executives employed by the plant’s owners Ineos.
Mr Carr’s report said there were “certain themes emerging” in the tactics used by unions in disputes such as Grangemouth, as well as industrial action on the London Underground and involving the fire and rescue service.
But the QC talked about the “one-sided nature of this evidence” over the allegations against unions, which were made by Mr Cameron and Tory politicians in the Commons.
The Prime Minister attacked the alleged behaviour of Unite during the Grangemouth dispute as “quite shocking” in the Commons last year, following claims by an Ineos director that a “mob” was sent by the union to his home to intimidate him during the dispute
Mr Carr said he had received a “relative lack of primary evidence” as the QC appeared to challenge the claims, which he suggested were “fundamentally difficult” to prove.
The QC has already said he not make any proposals for a change in the law, despite being asked by Mr Cameron to examine the existing legal framework to “prevent inappropriate or intimidatory actions in trade disputes”.
In a statement issued with his newly published report, said: “There are some employers who believe that they have been subjected to tactics during industrial disputes which they consider to be ‘extreme’. There were also certain themes emerging in the tactics used.
“However, the one-sided nature of this evidence, the relative lack of primary evidence received, and the inability to thoroughly test it through a question and answer process has made it fundamentally difficult for me to make any evidence-based judgement on either the extent or the ‘extremity’ of such a problem, should it exist.”