After conceding that he would "consider it a win" to keep his deposit in next week's Holyrood election, Lib Dem Andrew Metcalf was asked by ITV Border if the party should introduce women-only shortlists to get more female candidates.
"Women are not as strong, their physical body is not as strong as a man's physical body in general," said Metcalf, who is standing in the Galloway and West Dumfries constituency.
ITV reporter Kathryn Samson pointed out to Metcalf that you "don't need physical strength" to stand for the Lib Dems, to which Metcalf replied: "Absolutely, completely, totally agree, this is my point."
Asked again if the party should introduce all-women shortlists, Metcalf said: "No, because what we want is the best people for the job."
Metcalf's comments angered the Women 50:50 campaign, which argues that there should be equal representation between men and women in the Scottish parliament.
Scottish Lib Dem leader Willie Rennie said he would investigate the comments "urgently".
Rennie then tweeted on Monday afternoon that Metcalf was "very sorry" about the comments.
"I am very sorry about all of this," Metcalf wrote to Rennie. "I mishandled the interview. Of course I believe in women's equality. I am not used to TV media interviews in high profile elections. I apologise for any offence it has caused."
Talat Yaqoob, chair of the Women 50:50 campaign, told BuzzFeed News that Metcalf's comments were just the latest evidence of the sexism which which women still encounter in Scottish politics.
"I was glad to see the leader of the Scottish Liberal Democrats take the matter seriously and deal with it with such urgency," said Yaqoob. "However, the comments should never have been said and illustrate the sexism that women in politics, and across society, have put up with.
"We need more women leaders so we can erase this outdated myth that leadership is not for women. Scotland has no shortage of talented and able women – what holds them back are attitudes likes these.
"Political party candidates are usually provided with media training, perhaps it's time this included equality and diversity training too."
Jamie Ross is a Scotland reporter for BuzzFeed News and is based in Edinburgh.
Contact Jamie Ross at firstname.lastname@example.org.
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