The UK will fall silent on Tuesday in tribute to key workers who have died during the coronavirus pandemic.
Downing Street has confirmed Boris Johnson will be among those observing the minute's silence at 11am.
The PM resumed his full duties on Monday morning, three weeks after he was hospitalised with Covid-19.
Government workers will be asked to take part in the tribute and Mr Johnson's official spokesman said it is hoped others will participate "nationwide".
The Unison union, the Royal College of Midwives and the Royal College of Nursing launched a campaign last week for the nation to take a moment to honour frontline staff who have died during the Covid-19 crisis.
Between them, the organisations represent more than a million NHS and public service workers including porters, refuse collectors and care staff.
On Monday, the PM's official spokesman said: "We will be supporting the minute's silence.
"We will be asking everybody who works in the Government to take part and we would hope that others will take part nationwide as well."
It follows the weekly Clap for Carers initiative where Brits across the country applaud NHS staff from their doorsteps and windows to say thank you for battling the pandemic.
Dame Donna Kinnair, chief executive and general secretary of the Royal College of Nursing, said: "I am very pleased the Prime Minister is going to be taking part in the silence tomorrow.
"This moment will bring together a sombre but grateful nation. Whether in nursing or driving buses, our heroes kept going to work when many had the luxury of staying at home. Nobody should go out to work and risk their life.
"This must not be the last time that sacrifice is recognised. The country and its leaders owes a tremendous debt to these key workers and the many more who are on shift again today."
Tuesday's silence will coincide with International Workers' Memorial Day.
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More than 90 frontline NHS workers have died since March 25, and there have also been lives lost in other key sectors, including private social care and transport.
