Michael Gove has joked his lack of blond hair is behind his lack of power in Theresa May's new Government.
The former Tory leadership hopeful, making his first speech since returning to the backbenches, said MPs had learnt new Education Secretary Justine Greening was "slightly less blonde" than universities minister Jo Johnson.
In a line which could also be viewed as a jibe at Johnson's Foreign Secretary brother Boris, Gove added: "But one of the things his observation has reinforced in my mind is that blondness is clearly a quality that brings preferment under this new Government, and I know where I went wrong."
Former Education Secretary Gove entered the race to become Tory leader hours before nominations closed - a move which forced Boris Johnson to withdraw.
The pair had campaigned for Britain to leave the EU during the referendum campaign.
Gove later lost his job as Justice Secretary to Liz Truss.
But he has not wasted time in returning to the Commons and was among several MPs to express their thoughts on the Government's Higher Education and Research Bill.
Shadow education secretary Angela Rayner teased Gove over his failed leadership bid.
She told MPs: "We also heard from a new backbencher (Gove). We heard from him quite a lot during this debate.
"He didn't like the length of (shadow education minister Gordon Marsden's) speech earlier, but perhaps that's because it lasted longer than his leadership bid."
Rayner's remark prompted one mocking shout of "cheap" within the chamber, with other MPs laughing at the joke.