Reform UK says it would pay members of the public for tip-offs that lead to successful prosecutions of High Street shops employing illegal workers if it gained power.

The party’s home affairs spokesman Zia Yusuf said financial rewards under a “Turkish barbers tip line” would be paid from larger fines it would impose on firms using illegal employees.

It has pledged to fine larger firms up to 10% of their global revenues, and imprison the bosses of companies employing illegal migrants.

The Home Office said it was already increasing penalties for companies hiring illegal workers. A source within the department called some of Reform’s proposals “empty posturing”.

Reform said that if it won the next general election, it would make chief executives and directors of large companies profiting from illegal workers personally and criminally liable.

That would be regardless of their knowledge of workers’ legal status.

The party said this would be similar to the personal liability of senior managers for the financial misconduct of their firms under Financial Conduct Authority rules.

Reform said it would also introduce a tip line for the public to report suspected illegal working or organised criminal activity.

Speaking at a news conference to unveil the policy, Yusuf said Reform would make it a legal duty for local authorities to investigate every “credible report” they receive.

He said the reward scheme would emulate a system in the United States that rewards whistleblowers with a share of fines imposed after successful prosecutions of serious financial crime.

He added: “In terms of the exact percentage, that would be in the final legislation that we pass.”

Companies have a legal responsibility to verify that people they employ directly have the right to work in the UK. For agency workers, the responsibility lies with the agency to conduct the relevant checks.

Last year the Labour government extended this requirement to self-employed contractors carrying out work on behalf of a company, as part of a bid to improve enforcement in casual jobs in the so-called gig economy.

There are sanctions including fines of up to £60,000 per unauthorised worker, but Yusuf said there was a need to increase the scale of the penalties, adding they only presented a “minor inconvenience” for bigger firms.

A Home Office source said of Reform’s announcement: “The government is already doing much of this. The rest is just empty posturing.”

A spokesperson for the department added: “We are already closing the loopholes that allow illegal migrants to work in the UK by extending right to work checks to the gig economy and delivery sector.

“Employers who break the law face severe consequences, including fines of up to £60,000 per illegal worker, business closures, licence revocations and prison sentences of up to five years.”

They added that since Labour came to power, Immigration Enforcement action has increased “to the highest level in British history, with illegal working arrests up by 83% and raids up by 77%.”

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