While the number of people on zero-hours contracts has soared to an all-time high of one million, a workers’ rights crisis is unfolding for them.

Charity Citizens Advice warns that these insecure workers – half of whom class themselves as key workers – were more likely to face employment rights issues, job losses and reduced income amid the pandemic.

Its research revealed that on average, they’re four times more likely to have faced losing their job; three times more likely to have been made to work while ill and not received wages for hours worked; and one and a half times more likely to have lost an average income of £1,000 a month since March.

In one case handled by the charity, an agency worker was told to self-isolate and sent home without pay from her factory job after she told management she was pregnant. Another agency worker was denied sick pay they were entitled to after testing positive for Covid.

Citizens Advice added that many insecure workers are struggling to understand their rights or defend them “due to a complex and patchwork system for employment enforcement”.

Further, they were often denied access to the furlough scheme.

Alistair Cromwell, acting chief executive of Citizens Advice, said: “Zero-hours and agency workers, including delivery drivers and carers, have often been at the frontline of this pandemic.

“Yet they’ve faced a triple hit of hardship: more likely to face losing their jobs, have their employment rights violated and experience stark drops in income.

“It’s not right that the rights insecure workers have aren’t always being upheld. The government must fast-track its plans to create a one-stop shop for employment rights to ensure that all workers, including people in the most precarious positions, are protected.”

Frontline staff at Citizens Advice have helped more than 170,000 people with one-to-one advice on employment issues since lockdown. The charity has seen an 89% increase in people seeking help because of issues with the terms and conditions of their temporary, agency or zero-hours contract compared to the same period last year.

There are six national organisations which enforce workers’ rights, but workers who have been unfairly sacked or treated often can’t call for their situation to be investigated. While they could take their issue to an employment tribunal, previous research by Citizens Advice showed the employment tribunal backlog could pass 500,000 cases as a result of Covid.