The Queen will also thank NHS workers in a speech to the nation on Sunday, Buckingham Palace says.
The new Labour leader also says ministers should publish their "exit strategy" for restrictions.
The men are both thought to have been in their 60s and were support staff at Pentonville Prison.
A child with underlying health conditions is among 708 people whose deaths were reported in the past day.
Most stuck to the social distancing rules, minister Michael Gove says, but some young people did not.