On the subject of a potentially hard Commons vote, Mr Johnson said that was "taking too many fences at once". "Which is why we are saying please get your vaccine or your second dose when your turn comes".
SPI-M said that a new peak could occur in summer or autumn, and that its timing and size would depend on how people behave after restrictions end. The four-step plan is expected to see all legal restrictions in England being removed by mid-June.
The issue of vaccinepassports has been hotly debated around the world, raising questions about how much governments, employers and venues have a right to know about a person's virus status.
Almost 31.6 million people have been given the first jab of the coronavirusvaccine, according to the official figures.
Britain said on Monday it was too soon to say whether or not worldwide summer holidays could go ahead this year, suggesting a planned reopening of outbound travel could be pushed back beyond May 17.
The prime minister stressed that he does not want to "underestimate" the risk of travelers importing the virus into Britain.
The Scientific Advisory Group for Emergencies (SAGE), which advises the government, said that the move would not overwhelm the state-run National Health Service (NHS) even if infections rose assuming the country's successful vaccine programme stays on track.
He said the government is being careful to avoid a system which is "discriminatory", as some people such as pregnant women can not get vaccinated for medical reasons. People will not need vaccine certification for pubs, hairdressers and shops, Johnson said.
"You've got to be very careful in how you handle this and. don't start a system that's discriminatory".
He added: "I know that people watching will want to know exactly what they can do from May 17th but we're not there yet".
He added that large-scale events will "absolutely" need measures such as testing when they are allowed to go ahead again.
The prime minister said that more information will be given later this week.
It also confirmed that the government was looking at a COVID-status certification system, or vaccine passport, to help reopen larger events.
He explained there are three ways COVID certification can be granted "for a big mass event" - immunity after contracting the novel coronavirus in the past six months, proof of vaccination, and a recent negative test.
From Thursday, those living in England will be able to access two free rapid virus tests per week, a measure aimed at curbing symptom-free virus spread.
The lateral flow tests will be available at workplaces, community sites, schools and colleges.
Boris Johnson said he was "hopeful" that the earliest possible resumption date of May 17 can be achieved but warned of rising case numbers in some overseas destinations.
The UK government has promised to supply everyone in England with two quick-result lateral flow tests each week in a bid to cut the chain of transmission as the lockdown eases.
"Of critical importance will be moving countries - transparently - through the tiers into "green", reviewing measures urgently in light of the latest and best available evidence so that they are effective but also proportionate to the risk, and crucially embracing cost-effective rapid testing thus ensuring the alignment of global travel with the domestic economy, which will be so important for the UK's economic recovery". The total number of coronavirus-related deaths in Britain now stands at 126,862.
Latest government figures released on Monday showed another 2,762 cases had been confirmed, and a further 26 people had died with coronavirus within 28 days of testing positive.
Quarantine-free New Zealand-Australia travel to start this week
New Zealand's tourism sector would be crossing fingers for a start before the country's next long weekend - Anzac Day, April 25. Air New Zealand (pictured) are already offering flights between Auckland and Sydney as well as Melbourne from Friday, April 9.
When can I register online for the COVID-19 vaccine in BC?
He has consistently refused to push for more drastic lockdowns used in other countries, calling such tactics "authoritarian". The province set records two days in a row last week, with 1,018 cases reported for Friday and 1,072 cases Saturday.
Former Jordanian Crown Prince 'under house arrest'
Majali told Roya "No one will be more compassionate to Prince Hamzah than his big brother His Majesty King Abdullah II ". Jordan's traditional allies, including the US, Saudi Arabia and Egypt, have expressed support for King Abdullah.