The government’s social mobility tsar has said she does not think Boris Johnson is a good role model for children.

Katharine Birbalsingh, who was appointed chair of the Social Mobility Commission (SMC) in 2021, told Sky News that while she liked the prime minister she did not think he was “professional enough”, adding his personal life makes her “raise an eyebrow”.

Birbalsingh, the head of Michaela community school in Wembley, who was recently the subject of a documentary called Britain’s Strictest Headmistress, was asked if she believed Johnson was a good role model.

She said: “No, I don’t think so. I wish he could be, but he isn’t and that is a bit sad. I like Boris, I don’t think he’s a bad guy you know, but I don’t know enough about what he’s got up to, but I do not think that he is a good role model for children.”

When pushed on why she believed this, she said: “His personal life, for instance, that does make me raise an eyebrow. The other day I saw a picture of him in the Metro and I looked at his hair and I thought, oh my goodness, we expect our children to have professional-looking hair.

“Now, you might think that’s a bit pedantic and that’s a bit silly, but it isn’t actually. It’s important to look professional and sometimes Boris looks professional, but sometimes he’s not professional enough for me. Put it that way.”

In her inaugural speech as the SMC’s chair, Birbalsingh appealed for a radical rethink of what social mobility means, saying it should not just be about opening up elite pathways for the few.

She argued that widening access to university has “not always brought the dividends hoped for”, although more than 80% of sixth-formers at the school where she is headteacher went on to Russell Group universities last year.

Responding to Birbalsingh’s comments, the schools minister, Robin Walker, told Sky News she was “entitled to her opinion” but disagreed.

He said: “I think actually anyone who leads this country is a role model – someone that children can look up to. The prime minister has shown phenomenal resilience through the Covid pandemic and leadership, and I think that’s something that children should learn about in schools.

“He’s also a great communicator, and one of the things that we seek to teach in all of our schools is communication – literacy through great speech and language. So there’s plenty for people to look up to in that respect.”