UK law has granted protection for those who raise concerns of potential wrongdoing in the workplace (whistleblowers) since 1999 through the Public Interest Disclosure Act 1998.
The EU, when considering what its own whistleblowing protection laws should look like, recognised that the UK already grants comprehensive protection for whistleblowers. Nevertheless, there are differences between the position in the UK and the requirements of the EU Whistleblowing Directive (the “Directive”) which Member States were required to transpose into domestic law by 17 December 2021.
https://www.kingsleynapley.co.uk/insights/blogs/employment-law-blog/whistleblowing-in-the-uk-a-summary