Mothers with school-age children are being told they cannot work from home during the coronavirus pandemic, while fathers at the same companies are encouraged to do so, according to organisations providing legal advice and support for parents.

Legal advice lines have also been inundated with calls from pregnant women who have been made redundant while male workers have been kept on, and others who have been told they must go to work or face the sack despite being categorised as a vulnerable group in government guidance.

“We are seeing parents, the overwhelming majority of them mothers, getting in touch to say their employers are not letting them work from home because schools have closed, and in some instances their male colleagues have been allowed to do so,” said Julia Waltham, the joint head of policy and influencing at the charity Working Families. “Too often it is women who are expected to take up the slack at home and many mothers are feeling very vulnerable about work at the moment.”

Anna (not her real name) said her pay had been cut and hours reduced since the crisis struck. “I’m constantly being advised to reduce my hours as I can’t possibly manage two kids and my job at home,” she said. “It’s only the women that get asked on calls how they are managing – the men with childcare are fine to work as normal.”

Quick guide UK lockdown: what are the coronavirus restrictions? Show Hide What do the restrictions involve? People in the UK will only be allowed to leave their home for the following purposes: Shopping for basic necessities, as infrequently as possible

One form of exercise a day – for example a run, walk, or cycle – alone or with members of your household

Any medical need, to provide care or to help a vulnerable person

Travelling to and from work, but only where this is absolutely necessary and cannot be done from home Police will have the powers to enforce the rules, including through fines and dispersing gatherings. To ensure compliance with the instruction to stay at home, the government will: Close all shops selling non-essential goods, including clothing and electronic stores and other premises including libraries, playgrounds and outdoor gyms, and places of worship

Stop all gatherings of more than two people in public – excluding people you live with

Stop all social events, including weddings, baptisms and other ceremonies, but excluding funerals Parks will remain open for exercise, but gatherings will be dispersed.

Working Families has written to the chancellor, Rishi Sunak, – who last week announced the state would cover up to 80% of the salary of “furloughed” workers if companies kept them on their payroll – to ask the government to remind employers they could be exposing themselves to sex discrimination cases.

The charity, which has detailed advice for parents, praised action already taken to protect workers but called for clear messaging that employers should be as flexible as possible and staff should not be automatically furloughed. “If employers make wholesale decisions to ‘furlough’ one working parent in each working family, all the evidence suggests that it is overwhelmingly working mothers who will be put in this position,” the letter says.

Joeli Brearley, the founder of the Pregnant Then Screwed campaign, said hundreds of pregnant women and mothers had called for advice and support since UK schools closed on 20 March, leaving millions of families juggling childcare and work commitments.

“Yet again it is women scooping up the unpaid labour to keep things ticking over during a crisis,” she said. “We are seeing companies telling staff to work from home but denying women with kids that possibility, and we’re seeing pregnant women laid off without any sort of process while others are told they have to come into work.”

Sarah (not her real name), who is pregnant and works in a call centre that arranges hire cars, was told she had to continue working as the firm’s staff have been classified as key workers and cannot work from home. She was advised that if she followed government guidelines and self-isolated for 12 weeks the company could not guarantee her pay.

Pregnant women taking sick pay in order to self-isolate could also find they are not eligible for statutory maternity pay (SMP), which is calculated on the amount they get paid in the two months before the end of the 15th week before the baby is due.

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Claire, who works in customer service for a car insurance company, said she was not allowed to work from home even though she was 22 weeks pregnant, in the SMP qualifying period, and most of her colleagues were working remotely. “My family is putting pressure on me to stay home and not put myself or the baby at risk. I’m so stressed I don’t know what to do,” she said.

Brearley said many low-earning women would not currently qualify for statutory sick pay. According to research from the Trades Union Congress, 1.4 million female employees earn less than £118 a week – the qualifying threshold for statutory sick pay – while about 70% of those who do not qualify for statutory sick pay are women. Research by KPMG found 26% of working women earn less than the living wage (about 3.4 million women), compared with 16% of men. A Survation poll of women earning below the living wage found a third had no savings and 61% had savings to cover a month or less.

“Many of the women we have spoken to, particularly single parents, are telling us they suddenly have no income, no way of paying their rent or buying food for their kids,” Brearley said. “It’s a horrible situation, and it’s been really stressful being at the coalface of that without any clear advice from the government to give.”

Women’s rights groups have warned that the current gender-blind response to the coronavirus crisis risks setting gender equality back years, and called for the needs of women to be factored into policymaking. This week more than 50 organisations signed a statement calling on the government to consider the specific challenges faced by women, while women’s organisations are gathering data on how the crisis is affecting women specifically.

Sam Smethers, the chief executive of the Fawcett Society, said women were more likely to be on the frontline delivering essential services, in low-paid and insecure work and caring for children and older relatives, as well as significantly more likely to be put at risk of self-isolating with an abusive partner.