The peer, a former director general of Saga, urged firms to voluntarily incorporate “family care leave” into contracts, otherwise millions of valued and experienced workers could be forced to retire early. Lady Altmann is leading a task force of business and union leaders to develop a form of flexible leave to avert the potentially crippling exodus of experience from the economy.

According to the census in 2011, approximately 6.5 million people in the UK have caring responsibilities including more than two million who have given up work for their duties.

Carers UK, a charity, estimates that a further three million people have had to reduce their working hours to fit in with caring responsibilities. The number of people suffering dementia is predicted to rise from 800,000 to more than one million by the end of this decade and to double within 30 years.

Yet at the same time, there will be millions more approaching what was once retirement age in full health, not only wanting to continue working but needing to for financial reasons.

The right to request flexible working, originally designed for parents of young children, was extended to all employees, including carers, under the Coalition government. But there have been calls for a change in the law to give people a legal right to care leave.

Lady Altmann, who is not planning new laws forcing firms to act, said: “The idea is for more employers to start recognising the need to care for loved ones is inevitably going to go way beyond just children.

“This would allow people to take time for some kind of family crisis, whether it is a partner that has a stroke or a parent who becomes disabled – time to arrange care.

“We all want to look after loved ones. The problem is that often when that happens someone in their late 50s, who can be among the most valuable employees, feels they have to stop [work].

“The ‘family’ tends to be thought of as parents and children. But actually it can now be across generations.”

Stephen Alambritis, formerly of the Federation of Small Businesses and now leader of Merton Council in London, said: “There will be concern. To give time off for deliberate known events, like discharges from hospital, could be more difficult for smaller employers.”