Jeremy Corbyn's suggestion that women-only train carriages could be introduced at night to guard against sexual attacks has been condemned by rival Labour leadership contenders and anti-sexism campaigners.
The surprise favourite in the election to be Labour leader raised the issue amid a climate of growing concern about sexual harassment on public transport.
But the Everyday Sexism Project described women-only carriages as "a real step backwards" while leadership candidates Yvette Cooper and Liz Kendall both insisted it was not the appropriate solution.
The number of sex offences on Britain's railways increased last year, according to figures from British Transport Police (BTP).
There were 1,399 sexual offences in 2014/15, up from 1,117 the previous year.
Transport for London has begun a campaign to encourage more reporting of sex crimes on the capital's Underground network.
Launching his street harassment policy, Mr Corbyn said: "Some women have raised with me that a solution to the rise in assault and harassment on public transport could be to introduce women-only carriages.
"My intention would be to make public transport safer for everyone from the train platform, to the bus stop, on the mode of transport itself.
"However, I would consult with women and open it up to hear their views on whether women-only carriages would be welcome - and also if piloting this at times and on modes of transport where harassment is reported most frequently would be of interest."
Reverse the increase in sex crimes
Transport minister Claire Perry last year indicated she was interested in exploring the idea of women-only carriages, which are in operation in Japan, India, Brazil and other countries.
She said she was determined to do ''whatever we have to'' to reverse the increase in sex crimes and boost safety.
''They have introduced women-only seating in Japan because there is a particular problem with groping and low-level violence,'' she said.
''It is a very interesting question and I will look at all ideas.''
Laura Bates, of the Everyday Sexism Project, said Mr Corbyn's plan to consult with women was "the way forward", but she was strongly against the proposal.
"In terms of the issue itself, I think it would be a real step backwards," she said.
"It sends the message that harassment is inevitable, perpetrators are unable to help themselves and women should simply find a way round it."
Ms Bates added that it could exacerbate a culture of blaming the victims of sexual attacks.
"Imagine if a woman is assaulted in a mixed carriage if a women-only carriage is available," she said.
Senior Tory MP Sarah Wollaston also voiced her opposition to women-only carriages.
The Health Select Committee chairwoman tweeted: "Segregating women on public transport doesn't protect anyone, it just normalises unacceptable attitudes."
Ms Cooper, one of the four candidates for the Labour leadership, said: "Segregation to 'keep women safe' is turning the clock back, not tackling the problem. We shouldn't have to shut ourselves away from men for our own safety.
"The staff needed to enforce the segregated carriages should be keeping all the carriages safe instead."
Ms Kendall said: "Everyone should be able to travel without fear of physical or verbal attacks, and we have much to do as a society to reach that point.
"However, I don't believe that gender segregation is the answer. That would be an admission of defeat, rather than a sustainable solution."