Ken Clarke has launched a stinging attack on the media for acting like a "lynch mob" against Cabinet colleagues Jeremy Hunt and Baroness Warsi.
The Justice Secretary dismissed some of the allegations against the Tory peer as "downright silly" and "pedantic".
The comments came as David Cameron delivered a strong signal that Lady Warsi's job was safe despite ordering an investigation into her failure to declare business links.
The Prime Minister said he was "very happy" with the Conservative Party chairman's explanation after it emerged she took relative and business partner Abid Hussain on an official trip to Pakistan.
He also dismissed accusations that he was employing double standards by resisting an investigation into Hunt, saying the two cases were "very different".
Hussain accompanied the Tory peer when she visited Pakistan in July 2010, soon after the coalition came to power.
In a letter apologising to the Premier, Lady Warsi described Hussain as a "community activist" who had helped the British High Commission with outreach events.
Although it was "widely known" that Hussain was her husband's second cousin, she had not realised the need to declare that they also had "a common business interest as minority shareholders in a small food company".
"In retrospect, I accept that I should have made officials aware of the business relationship between Mr Hussain and myself, and for this I am sorry," she wrote.
Cameron responded that there were "clearly some issues for future handling" and his independent adviser on ministerial interests, Sir Alex Allan, would be considering "the issues that have been raised with respect to the Ministerial Code".I
In broadcast interviews, the Prime Minister batted away suggestions that Lady Warsi was being treated more harshly than Mr Hunt, who has not faced investigation by Sir Alex over his handling of News Corporation's BSkyB bid.
"They were two very different cases. In the case of Jeremy Hunt, obviously all of that has been gone through by the Leveson Inquiry," he told Sky News.
"In the case of Sayeeda Warsi, I am very happy with the explanation she has given. She has apologised for the mistake she has made but I think it right for Sir Alex Allan just to see if there are any loose ends that need to be picked up. It's no more than that."
Clarke told BBC Radio 4's PM programme it was right that senior politicians were put under "very close scrutiny".
"But there is a bit of a fashion at the moment, the media do tend to act as a bit of a pack and they are steadily working through my colleagues trying to find things to complain about," he said.
"Sayeeda (Warsi), I am astonished by some of the complaints against her. It really is pedantic, some of it.
"The question of this guy who went with her to Pakistan, who is a relative, whether or not he was going there in any way which furthered a business interest will now be looked at by Alex Allan."
Clarke said journalists did sometimes become a "bit of a lynch mob, racing about finding extraordinary things to complain about".
"Some of the ones against Sayeeda frankly were downright silly," he went on. "Alex Allan will have a look at it and I trust Sayeeda will be able to satisfy him that there was no impropriety."
Although he stressed he had not discussed the matter with the Prime Minister, Clarke said he presumed Lady Warsi was being treated differently to Hunt because she had not given evidence to Leveson.
Earlier, Tory backbencher Louise Mensch said Cameron had little option over referring the matter to his adviser, as Lady Warsi admitted making a mistake.
But she added: "As both the Prime Minister and Lady Warsi said in their letters, the breach is really pretty minor, based on the fact that the guy did not go out at taxpayers' expense and did not receive any financial benefit from the trip."
But fellow Conservative Nadine Dorries suggested that although the peer was "probably completely innocent", she should stand down while the investigation takes place.
"When she is found innocent, David Cameron should provide his full support and reinstate her," she told the Financial Times.
Labour frontbencher Michael Dugher said: "Doing the right thing by referring Baroness Warsi to the independent adviser on the Ministerial Code only exposes David Cameron's failure to act in relation to Jeremy Hunt."