Commons education committee chairman Barry Sheerman has admitted he was involved in bullying at school.
Mr Sheerman said he would like to meet the pupils affected
The Labour MP for Huddersfield said he and a friend had made the lives of two cadet force colleagues a "misery" because they "could not march in step".
Mr Sheerman said he had forgotten about it until he was reminded recently.
He told a committee meeting: "It is very interesting that you can assume that your school days were bully-free, and it brought me up very sharply."
Mr Sheerman's committee was looking into the problem of bullying, when he reminisced about speaking to an old friend recently.
He added: "He said, 'What about those two boys who could not march in step in the cadet force?' and we made their lives a misery, and I had totally forgotten that."
When asked about his past on BBC Radio 4's PM, Mr Sheerman said: "I think part of bullying is you don't even know when it's happening or even when you're participating or supporting it.
"I was boasting to an old school friend that I'd never known any bullying at my school - which was a boys' school - but he said, 'Don't you remember how miserable we made those two boys who couldn't march in time?'
"And I looked back and I suddenly thought 'You know, that was bullying. We made these two boys' lives a misery'."
"When I look back, they were I think, a couple of young men who had some difficulties, physical difficulties.
"I would love to meet them and talk to them and say that I understood, looking back, just what I may have - and the group of classmates - made them feel."
The charity Beatbullying said a third of all pupils aged between 11 and 17 in England admitted to truanting at least once because of bullying.
The education committee heard that there more incidents of racist bullying than reported.
Many schools were reluctant to make public such incidents for fear of ruining their reputation, anti-racism campaigner Shobha Das said.