Councils will be able to draw upon a £4m fund to cover the bill for giving residents a rebate while they are out of their homes.
The councils will not be forced to introduce the payment exemptions, Number 10 said.
More top news
The actress attended the annual dinner dressed in purple and sporting a temporary tattoo in tribute to pop star Prince who died last month.
Charity says there has been a big rise in employees unfairly treating pregnant women and new mothers.
Sadiq Khan has said that his prospects of being elected London mayor could be damaged by the party's poor handling of racism accusations.