All workers forced to retire since 1 October this year have been urged to lodge age discrimination claims after a High Court ruling last week.
A senior judge ruled the challenge to the government's mandatory retirement age, brought by baby-boomers' group Heyday, should be referred to the European Court of Justice (ECJ).
This leaves employers open to paying compensation to anyone they force into retirement before a ruling is made - which might not be for another two years.
Andrew Harrop, the head of policy at Heyday, told Personnel Today: "Employees should make applications now if they have been forced into retirement. The claims will be put on hold pending a European judgment. My advice to employers is not to take the risk and not to force people to retire."
Heyday claims that up to 25,000 people are retired against their will each year.
Owen Warnock, employment law partner at Eversheds law firm, said public sector organisations were at extra risk of claims as they were bound by the "intent" of European law, while private sector firms could argue that they complied with UK law.
Sam Mercer, director of the Employers Forum on Age, "strongly recommended" that employers consider operating without a retirement age.
The judge referred the case to the ECJ after the government agreed with Heyday that its transposition of a European law should be scrutinised. The Employment Equality (Age) Regulations came into force in the UK on 1 October to implement the EU Framework Directive from 2000.
Heyday told the High Court that the UK law was illegal, as it discriminates against people on the grounds of age.
Robert Allen QC, speaking on behalf of Heyday, argued that people aged 65 or over were given "second-class status", as they could be retired without explanation. People under 65 had to be given sound grounds for dismissal, he said.
The government countered that, from the age of 65, people were "not in comparison" with under-65s, as they rece