The news comes as the Employment Relations (Flexible Working) Bill is due to reach its third reading in the House of Lords next month (14 July).
Under the new plans, employees will be able to request changes to their working hours, times, or location from day one of employment.
Managers will also have to provide proper reasoning for rejecting an employee's request for flexible work.
More on flexible working:
Emma Stewart, co-founder of Timewise, said employers need to be proactive in preparing for the influx of requests.
Speaking to HR magazine, she said: “We know a wave of requests are coming when this legislation goes through, and HR needs to think carefully about their response and decide their policies now.
“Otherwise, the unintended consequence is that staff who are more informed and know about the bill will end up with different options available to those who aren’t, which could lead to tension and inequality down the line.”
For new starters, Stewart recommended employers clearly set out the available options as early in the recruitment process as possible.
She said: “The best way of doing this is to make sure that you're doing it through your advertising, so you're both prepared for the conversation and you've agreed what would be possible right from the beginning.
“It will avoid a lot of uncomfortable conversations.”
There was a small disparity between the percentage of men who would ask for flexible working (48%) and women (51%) who would do the same.
A larger disparity was found between workers from different ethnic backgrounds: 61% of workers from black, Asian and mixed ethnic backgrounds said they would consider making a request from day one, following the introduction of the bill, compared with 48% of workers from a white background.
This disparity was particularly noticeable among black respondents specifically, 71% of whom said they would consider making a request.
Timewise suggested this difference may be indicative of workers from ethnic minorities currently thinking flexible working requests will be ill-received due to racial bias.
More than a third (37%) of workers from black, Asian and mixed ethnic backgrounds backgrounds said they would not feel comfortable talking to their current employers about changing their working pattern.
Only 28% of workers from a white background shared those concerns.
Shabna Begum, director of research race equality think tank Runnymede Trust, said: “Many black and minority ethnic workers experience the labour market on unequal and unfair terms.
“The right to day-one flexible working would be a welcome enhancement to support those workers who might experience their workplace environment as unfriendly or sometimes hostile and provide them the confidence they need to access better conditions.”
Stewart said employers can help make flexible working feel accessible to everyone through how they characterise the people that need it.
She said: “Firstly, employers can look at their recruitment advertising, making sure they use gender neutral, non-biased language, and that imagery for flexible working is not always a woman with a baby typing on a laptop.
“Secondly, in terms of your communication with people, focus on the ‘how’ and not the ‘why’ of flexible working, because there shouldn’t be a bias towards certain needs.
“We’ve seen examples in the past in which women with childcare responsibilities have been able to get flexible working, but not people with health conditions, or who are neurodiverse, or even people who want to manage a portfolio career.”
Stewart also emphasised the need for training at all levels of an organisation, including line managers.
“Make sure that managers are getting proper training in how to be able to communicate different ways of working flexibly and how to have those conversations with people," she said.
“And that's just often about supporting managers to be really open and honest about what's available, and what could work, and not feeling afraid to have the conversations because they're nervous about saying the wrong thing.”
Timewise surveyed 4,000 UK workers between 27 March and 9 April 2023.