His quick answer was that it was wrong to use a defence dating back to 1689 in this day and age.
And some might agree, how can archaic laws possibly apply in this modern age.
But hang on, there's a lot of law out there and just because it's old, doesn't make it bad per se.
For instance, habeas corpus, the law which allows us to take action against unlawful detention by the state, dates all the way back to 1215. I doubt somehow that Nick Clegg and the Lib Dems would rush to do away with habeas corpus simply because it's a bit long in the tooth - albeit that European arrest warrants have rather undermined it already.
Yes, there's a lot of arcane law on the statute books, but to say that something is wrong simply because it's old is rather a foolish argument.
One could equally say that old laws have stood the test of time and so encapsulate fundamental principles which have prevented the need for repeal over the centuries.
Nick Clegg might have justifiable objections to the use of parliamentary privilege, but let's hear something a bit better thought out that simply saying: It's an old law, it shouldn't be allowed. That just insults our intelligence.
Furthermore, he might not like the use of a defence of parliamentary privilege, but surely that's a matter for a jury to decide upon. I would have thought that a Liberal leader, of all people, would defend principles like the presumption of innocence and right to a fair trial, even of his political opponents. Unless of course, that chance to score a few points before an election means the temporary setting aside of such principles.