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.
A study carried out by Middlesex University and supported by the Department for Transport and British Transport Police (BTP) concluded that women-only transport would be "a retrograde step".
The number of sex offences on Britain's railways increased last year, according to figures from 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, while BTP has a range of regional schemes designed to reduce harassment.
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."
Rail 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.
But following Mr Corbyn's comments she released a statement which read: "Experts and campaigners agree that segregation is not the solution.
"Our approach focuses on catching and punishing offenders rather than segregating people and the raft of unintended consequences that would involve."
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."
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."
Ms Kendall said: "I don't believe that gender segregation is the answer.
"That would be an admission of defeat, rather than a sustainable solution."
Leadership rival Andy Burnham dismissed the suggestion of women-only carriages.
He said: "I want to see a proper society-wide strategy on tackling violence against women."
David Sidebottom, passenger director at the independent watchdog Transport Focus, said: "Generally it is very safe to travel by train - almost eight in 10 passengers are satisfied with their personal security.
"Passengers tell us that they feel the best deterrent against crime is a visible staff and police presence on trains and at stations."
Unison general secretary Dave Prentis said: "Segregating women in transport would send the wrong message to those who think they can harass and abuse.
"It is more visible policing, better staffing at stations and on public transport and improved street lighting that can help women feel safer when travelling at night."