Scottish Gas owner Centrica is joining calls on the Government to introduce mandatory paid leave for workers who also have caring responsibilities.
Chief executive Iain Conn has written to the chief executives of the UK's 100 largest employers to encourage more support for carers.
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Centrica said it believed companies could save up to £4.8 billion a year in unplanned absences and a further £3.4 billion in improved employee retention by adopting flexible working policies to support those with caring responsibilities.
The firm is announcing a change to its carers policy, giving employees more paid leave, without using annual allowances.
It will now offer 10 days' paid leave to all carers followed by another 10 days that can be taken if matched with annual leave.
According to Carers UK, the number of people balancing care responsibilities with work has increased from three million in 2011 to more than five million.
The demands of caring mean that 2.6 million people have been forced to stop working altogether, said the charity.
In his letter, Conn said: "We have announced a change to our carers leave policy to give our employees more time off to care for their loved ones without using their holiday allowances. We will be applying these principles across Centrica globally.
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"We believe it's the right thing for businesses to do and at Centrica we want to support our employees and share best practices with other employers."
Helen Walker, chief executive of Carers UK, said: "More than 600 people give up work every day to care for a loved one, often taking with them skills and years of experience.
"Whether looking after a partner receiving hospital treatment, or supporting parents to live independently at home, a right to five to 10 days' paid care leave could make all the difference to a member of staff juggling work and care."
