Rebecca Long-Bailey today pledged a legal right for people to switch off their phone outside work.
The Labour leadership hopeful said she would end the “24/7 work culture” by giving employees the right not to be contacted outside working hours.
While her campaign team gave few details, a source said the policy would “eventually be a legal right”.
A “right to disconnect” in France obliges organisations with more than 50 workers to define employees’ rights to ignore their mobiles.
Ms Long-Bailey, who will give a speech and Q&A with journalists on Friday night, said in a statement from her team: “Aspirational socialism is about us all rising together.
“And that means coming together to collectively solve issues that are damaging our mental health and stopping us getting quality time with our families or in our communities.
“We can all do better with aspirational socialism, through pushing for an end to the 24/7 work culture, and with trade unions empowered to negotiate this, we can work hard, be paid for the work we do and keep that precious time with our friends and family, uninterrupted by emails or demands.”
But polls have put her rival Keir Starmer ahead with the Labour membership – and an Ipsos MORI poll yesterday suggested Sir Keir would have the best chance of attracting new voters to Labour.
The shadow Brexit secretary had the best score among his rivals with 32% of the public and 45% of Labour voters saying he has what it takes.
Some 35% of the public said they could back Labour with him in charge.
That compared to 28% saying the same for Rebecca Long-Bailey.
Sir Keir, Ms Long-Bailey and Lisa Nandy have all won sufficient support from groups affiliated to Labour to make it onto the postal ballot of members and supporters.
Emily Thornberry is thought to be struggling to make the ballot before the cut-off date of February 14.