Boris Johnson has urged the public to “follow the rules” to control the spread of Covid-19, as he set how the lockdown in England will be eased in the coming months.

The Prime Minister said it was right that the sacrifices made by the British people in order to drive down transmission of the virus were now acknowledged, and that the country will begin to take steps towards opening up.

He praised the “indomitable spirit of Britain”, but he told the Commons: “If the data goes the wrong way, if the alert level begins to rise, we will have no hesitation in putting on the brakes and delaying or reintroducing measures locally, regionally, or nationally.”

He added: “Our challenge is to find a way forward that preserves our hard won gains, while easing the burden of lockdown and I’ll be candid with the house this is a supremely difficult balance to strike.”

Mr Johnson set out his “road map” for easing restrictions, starting on Wednesday with people who cannot work from home – and in sectors such as manufacturing, food production and construction – urged back to work.

Garden centres will also reopen and people will be allowed outdoors for unlimited exercise in pursuits such as tennis, golf, lawn bowls and basketball.

However, they must keep two metres away from other people and only exercise with their own household.

People in England should also wear face coverings in enclosed places, such as in some shops and on public transport, Mr Johnson said.

People can meet with a person from another household outdoors as long as social distancing is maintained. It can be one person one day and a different person the next.

Driving to destinations for outdoor walks and exercise is also permitted. Fines for those who break the rules will rise to £100 in England.

The new document, which comes as the UK death toll neared 37,000, sets out future plans if the virus reproduction rate – the R value – can be kept below one.

These include:

– The Government’s Scientific Advisory Group for Emergencies (Sage) has been asked to look at the idea of a household “bubble” in the coming weeks, where one household is allowed to join up with and interact with one other household only

– International travellers will be asked to quarantine for 14 days when they enter the country, either in accommodation of their choice or provided by the Government if there are no other options. The date of implementation has not been announced

– The Government’s ambition is that all primary school children will be able to go to school for a month before the summer holidays

– Non-essential retail such as clothes and shoe shops could be able to open no earlier than June 1 if it can be proven they can keep people safe

– Pubs, bars, restaurants, nail salons, hairdressers, accommodation, gyms and cinemas will need to stay closed until at least July

– The Government is examining “how to enable people to gather in slightly larger groups to better facilitate small weddings” from next month

– Those who are currently shielding will be asked to continue doing so

– Those who are not in the shielded group but who are more vulnerable to Covid-19, such as the over-70s, should “continue to take particular care to minimise contact with others outside their households, but do not need to be shielded”

– Cultural and sporting events will be able to take place behind closed doors for broadcast from next month, thereby avoiding the risk of large-scale social contact

– Playgrounds, outdoor gyms and ticketed outdoor leisure venues will remain closed for now

The document also sets out how restrictions may be lifted and implemented on a regional basis, depending on local levels of infection.

The document says: “The Government may adjust restrictions in some regions before others: a greater risk in Cornwall should not lead to disproportionate restrictions in Newcastle if the risk is lower.”

An annex to the document says people are unlikely to get infected if they walk past somebody in the street, but they should avoid standing face to face with somebody where possible, with standing side to side offering a lower risk.

People are also urged to continue washing their hands regularly and to wash their clothes often if they work with people outside the home.

Indoor places should also be well ventilated.

On schools, the document says approximately 2% of children are attending school in person, but says schools should urge vulnerable children and those of critical workers to attend.

The Government is also amending its guidance to clarify that paid childcare, for example nannies and childminders, can happen as long as good public health measures are adhered to. This could help parents return to work.

Nurseries are expected to reopen no earlier than June 1 – at the same time as reception, year one and year six return to primary schools.

The Government has yet to publish guidance on how workplaces can become “Covid secure”, but the new road map says “social-distancing guidance on public transport must be followed rigorously.”

The report says the Government is hoping a vaccine or drug treatments will be developed against Covid-19, but says this cannot be relied upon and a vaccine may never be found.

It comes as the Government estimates that, as of May 9, some 136,000 people in England are currently infected with Covid-19.

Mr Johnson told MPs: “Our struggle against this virus has placed our country under the kind of strain that will be remembered for generations, but so too, has the response of the British people.

“Let me summarise, by saying that people should stay alert, by working from home if you possibly can, by limiting contact with others, by keeping your distance to two metres apart where possible, washing your hands regularly, and if you or anyone in your household has symptoms, you all need to self-isolate.

“Because if everyone stays alert and follows the rules, we can control the virus, keep the rate of infection down and keep the number of infections down.

“And that is how you save lives and to save livelihoods as we begin to recover from coronavirus.”

Scotland, Wales and Northern Ireland have not lifted measures to the same extent.