London, March 29 British Prime Minister Boris Johnson has warned the coronavirus crisis "will get worse before it gets better", in a letter being sent to every UK household.
Boris Johnson, who is self-isolating after testing positive for Covid-19, says stricter restrictions could be put in place if necessary, the BBC reported.
Britons will also get a leaflet detailing government rules on leaving the house and health information.
It follows criticism over the clarity of government advice to date.
The number of people who have died with coronavirus in the UK has now reached 1,019, with a further 260 deaths announced on Saturday.
There are now 17,089 confirmed cases in the UK.
In the letter being sent to 30 million households at an anticipated cost of euros 5.8m, Johnson writes: "From the start, we have sought to put in the right measures at the right time.
"We will not hesitate to go further if that is what the scientific and medical advice tells us we must do."
"It's important for me to level with you - we know things will get worse before they get better," the letter reads.
"But we are making the right preparations, and the more we all follow the rules, the fewer lives will be lost and the sooner life can return to normal."
Experts have said they expect the number of coronavirus cases and deaths to continue to rise for the next two to three weeks, before the effects of social distancing measures and restrictions on everyday life begin to have an impact.
In his letter, Johnson describes the pandemic as a "moment of national emergency", urging the public to stay at home to protect the NHS and save lives.
He also praises the work of doctors, nurses and other carers as well as well as the hundreds of thousands of people who have volunteered to help the most vulnerable.
The leaflet sent alongside the letter includes guidance on handwashing, an explanation of coronavirus symptoms, the government rules on leaving the house and advice on shielding vulnerable people.
Meanwhile, new powers, including fines of up to euros 5,000, to enforce guidelines on people staying at home and businesses staying closed came into force in Northern Ireland on Saturday evening.
The maximum fine will be reserved for businesses but individuals could face a fine of up to euros 960 if they do not comply.
( With inputs from IANS )