Boris Johnson will stress the need for people to be cautious on Monday as England takes its first significant step towards easing lockdown restrictions for adults. People will now be able to meet up legally outdoors in groups of six, or in two households, including in private gardens, and organised outdoor sport can resume. The relaxation of restrictions is being accompanied by the launch of a government advertising campaign showing vividly why indoor mixing with people from other households is still deemed risky. In an unusual move, as part of the campaign, the Department of Health and Social Care (DHSC) is publicising advice from a psychologist about how people can resist pressure from their friends and relatives to break the rules. In a statement issued overnight, Johnson said: “We must remain cautious, with cases rising across Europe and new variants threatening our vaccine rollout. Despite today’s easements, everyone must continue to stick to the rules.” Johnson is expected to expand on this message when he holds a press conference on Monday afternoon, for the first time using the new media suite installed at 9 Downing Street at a cost of £2.6m. Although some press coverage has presented Monday as a first step on the road to freedom from lockdown, such language was notably lacking from the statement Johnson released overnight. A No 10 source said: “This one in particular, there’s very much a sense of caution, and doing things gradually, so that we can assess the data on the changes that we make, and be confident that we’re not going to have to go backwards.” The first move towards easing the lockdown in England came on 8 March, when schools reopened. But for most adults, the impact was limited because the only rule change with wide application was allowing people to meet one other person outside for a drink or exercise. The changes coming into force on Monday will have significantly more impact, allowing a much wider amount of outdoor socialising. Although parts of England are set for fine weather in the early half of this week, ministers fear that many outdoor meetings could easily end up inside. TV advertisements being shown for the first time on Monday night will illustrate why this makes the risk of coronavirus transmission much higher. Conscious that many people find it hard to resist peer pressure to meet up in a large group, or to head indoors with people from another household, the DHSC issued a statement overnight from Laverne Antrobus, a clinical psychologist, advising people how to resist. “[The new guidance] may mean being put in situations where you have to say no to joining a large group of more than six, or perhaps feeling pressured to go indoors with people outside your bubble,” said Antrobus, from the Tavistock and Portman NHS foundation trust’s family mental health team. “It is so important to set your boundaries and be assertive in those situations, and to continue following the guidance to keep yourself and your loved ones safe from the virus.” She also advises people that they “can say no” and that they should plan meetings carefully. The department is also encouraging Antrobus to give media interviews this week driving home the same message. Under Johnson’s roadmap to lifting lockdown restriction, step two, allowing shops, gyms and outdoor hospitality to reopen, is scheduled for 12 April; step three, allowing indoor meetings of up to six, or two households and overnight stays is scheduled for 17 May; and step four, involving the lifting of all legal limits on social contact, is scheduled for 21 June. These are supposed to be “not before” dates, which could be put back if the Covid situation deteriorates, but that point is not often stressed by ministers. Johnson will also announce on Monday that the Office for Health Promotion is being set up to tackle obesity and poor mental health. Modelled on schemes such as Singapore’s health promotion board, it will be tasked with tackling the top preventable risk factors causing death and ill health in England. But there will be no additional funding for the office, which will be resourced from the existing health budget. On Sunday the government reported 19 further UK coronavirus deaths, with the seven-day total for deaths down 32% on the previous week. There were 3,862 new cases reported, and the weekly total was down 2% from the week before. With 423,852 people in the UK getting their first dose of a vaccine on Saturday, more than 30 million people have now had their first jab – around 57% of all UK adults. And 3.5 million people, accounting for 6% of the adult population, have now received their second dose. On Sunday the government confirmed that the Moderna vaccine will start being administered in the UK next month, joining the Pfizer and AstraZeneca jabs already in use. Britain has ordered 17m doses of the Moderna vaccine, which has a 94% efficacy rate in trials, and it has been reported that the initial supply will be in the hundreds of thousands. Prof Adam Finn, a member of the Joint Committee on Vaccination and Immunisation, said the arrival of the Moderna supplies would be helpful, but not a “game-changer”. He explained: “It adds an extra string to our bow if you like and it gives us an extra line of security. But it’s not a profoundly different change of direction.”