The vicious campaign against Tory Party co-chairman Sayeeda Warsi, led by the Sunday Telegraph and backed by the Labour Party (see here, here and here), has suffered a setback.

The BBC reports that Warsi has been cleared of any serious breach of the ministerial code over an official trip to Pakistan. The prime minister’s adviser Sir Alex Allan found she had committed only a “minor” breach for failing to declare she had been accompanied on the trip by her business partner Abid Hussain, with whom she had set up a restaurant supply company called Rupert’s Recipes.

In his report, Sir Alex said: “Baroness Warsi has accepted that she should have made officials aware of her business relationship with Mr Hussain, and has apologised for the oversight. But, as she says, this was not a trade-related visit; Rupert’s Recipes does not do any business in Pakistan and there was no financial benefit to either Baroness Warsi or Mr Hussain; Mr Hussain was not a member of the official delegation, no part of his travel or other costs were met by the British government, and no arrangements were made by her office or the British High Commission for Mr Hussain to meet leading politicians.”

He added: “I am satisfied that, had she declared her business relationship, that would not have been seen as a barrier to Mr Hussain helping to organise the visit. Nonetheless, she should have been more aware of the perception of a conflict of interest, and the potential criticism which could arise.”

Sir Alex advised the prime minister: “Any action you decide to take in the light of the facts of this case is of course a matter for you, but I record my view that the breach of the code was a minor one, and that Baroness Warsi did not use her office for personal financial gain.”

In a statement Warsi said: “I have always maintained that I have never misused my ministerial office for personal or financial gain. The allegations on this matter were untrue and unsubstantiated, and I am pleased that Sir Alex Allan’s report has confirmed that.”

Nobody acquainted with the facts of the case could have believed that Allan’s investigation would reach any other conclusion. Warsi’s opponents must have known that. Their aim, however, has been to create enough controversy around her that it will be impossible for David Cameron to keep her on as Tory Party co-chairman.

They may still succeed. Despite the fact that Warsi has been cleared of any wrongdoing over the Pakistan trip, the Daily Mail reports that Cameron has “hinted he may move her to a different post”.