She certainly didn't take kindly to charity lawyer Hubert Picarda's remark that her recent report saying there should be no restriction on campaigning by charities was a "Trojan horse" for Government policy.
"Are you retracting those words?" Kennedy thundered back, in front of the 100 or so senior sector figures crammed into committee room 16. "This is disgraceful. Don't you ever suggest that."
She was probably already smarting from the suggestion by shadow charities minister Greg Clark that, as a Labour peer, she was the wrong person to have chaired the Advisory Group on Campaigning and the Voluntary Sector.
"It is true that Helena Kennedy often didn't see eye-to-eye with Tony Blair," said Clark. "Norman Tebbit rarely sees eye-to-eye with David Cameron, but that doesn't mean he's the best person for a non-partisan review."
He also attacked Kennedy's report for quoting Ed Miliband as saying "it is massively in the interests of politicians to champion your campaigning role". What he actually said, according to Clark, was "... the interests of progressive politicians". Clark growled: "And when a New Labour intellectual such as Ed Miliband uses a word like 'progressive', you know he means 'left-wing'."
Kennedy's call for a law change was supported by some. Most were concerned by confusion over the meaning of the word "ancillary" in the Charity Commission's rules and their disproportionate effect on small charities.
NCVO president Lord Hodgson, a Conservative peer, said Kennedy's wish to address the democratic deficit by allowing charities to concentrate on political campaigning was "to get the cart and the horse mixed up", while Labour MP Tom Levitt, who chairs the All-Party Group on the Community and Voluntary Sector, said his gut feeling was that a change in the law was "a solution in search of a problem".
No one admitted to changing their mind, but all agreed more debate was needed. Brian Lamb, director of communications at the RNID, said: "If you had said, even a year ago, that we would fill a committee room with an arcane debate about campaigning, I would have said you were mad."
If Kennedy and Picarda are on the bill again they might just have to book the House of Commons itself next time.