Sir Keir Starmer has called on Boris Johnson to form a "national consensus" on the next phase of the coronavirus response as ministers work on plans to ease the lockdown.
Labour has outlined seven principles that it wants the Government to consider when planning for the next phase.
These include enforcing a "national safety standard" for businesses and schools, setting an "ambitious target" for contact tracing and introducing bespoke support for individuals and industries facing huge challenges, such as the hospitality sector.
The Labour leader has backed the extension of the strict measures ahead of talks with the Prime Minister this week and pledged to work "constructively" with the Government.
But he continued his criticism of Mr Johnson's handling of the crisis, saying ministers have been behind on testing, protective equipment and implementing the lockdown.
"We want to support the Government to get this right and that is why we need a national consensus on what happens next," Sir Keir said.
"Our priority is protecting the public's health and saving lives. That is why we supported the lockdown and again support the restrictions staying in place at this time.
"However, we need to be honest with the public about the challenges ahead. We are in this for the long haul. It is imperative that the Government is properly planning for what happens next and properly supporting our NHS and social care services."
Sir Keir acknowledged public concerns about returning to work after more than six weeks of being told to stay home to protect themselves, loved ones and the NHS.
"People rightly need confidence it's safe before they go back out to work, travel or use public services," Sir Keir added.
The Government hopes the “test, track and trace” approach – eventually used alongside the new NHS app being trialled on the Isle of Wight – will allow it to take a localised approach.
So if a city such as Manchester, for example, became a virus hotspot after the lockdown had been eased, testing could begin on a large scale and contact-tracers deployed.
A source said: “If you saw a worrying increases of transmission in regions, then you would want to move quickly to try to stop those.”
Schools and non-essential shops could be closed, to help drive back down the crucial R transmission rate between people, while the rest of the country continued as normal.
Wearing face masks is likely to be the new normal for shoppers still fearing a second wave of the virus.
As part of the national easing of restrictions, the PM is expected to say primary schools could reopen for some pupils – most likely Year Six – as early as June 1.
But other tough restrictions will remain until there is a vaccine, with cinemas, pubs and theatres likely to stay closed for months.
And those who can work from home are expected to be asked to continue. Department of Business officials are drawing up guidance to get people back to work in the coming weeks.
Recommendations could include staggering shift times to ease the rush hour, avoiding hot-desking or sharing pens, closing lifts and canteens. Bosses are currently advised to keep workers two metres apart wherever possible.
