The government has ramped up its coronavirus public information campaign with a stark new approach, telling people they will be responsible for the deaths of others if they leave home.

One new NHS-branded advert running across social media and websites carries an image of a woman in protective clothing while the blunt warning flashes up saying: “If you go out, you can spread it. People will die.”

There has been a move to impose stricter message discipline on politicians during media appearances in recent days, with Downing Street boosting its communications team with the hiring of former Conservative party election chief Isaac Levido, to sharpen the public messaging. Sources previously told the Guardian that No 10 is increasingly in “campaign mode”.

Guidance on official government social media output is being provided by Ben Guerin from election-winning New Zealand political consultancy Topham Guerin, according to Whitehall sources, suggesting a more aggressive approach than that usually adopted by civil service-produced campaigns. His outfit is known for their use of online adverts that aim to cut through the cacophony of social media using simple, blunt messaging while also attracting controversy for stunts such as rebranding the Conservative press officer account as “Fact Check UK” while posting about the leaders’ debate in the last election.

Both the government and health officials have united behind the slogan of “Stay Home, Protect the NHS, Save Lives”, which is being repeated at every opportunity. The phrase, credited to former Michael Gove adviser Henry de Zoete, is now printed on a bright yellow background on lecterns during daily Downing Street press conferences, while also appearing on official public information adverts.

The government has also been able to take advantage of relatively cheap availability of commercial advertising, with many big companies reducing their marketing spend following the economic chaos caused by the coronavirus outbreak. Newspaper websites have been particularly badly hit, with many companies blocking their adverts from appearing alongside articles relating to the coronavirus outbreak, meaning many face an uncertain financial future even though their journalism has never been more popular.

The NHS has separately upped the promotion of its mental health campaign Every Mind Matters, amid concerns the public could be struggling to cope while staying at home and away from other people during the pandemic. The health service is running adverts on Facebook, Instagram, and Facebook’s Messenger service in a bit to increase awareness of the service which offers mental health improvement plans to the public.

They are also promoting advice for people worried about coronavirus, urging the public to talk to others about their worries, stick to trusted sources of information, and do their best to connect with people.

The government already has experience running large-scale communications campaigns, having recently spent £46m on last autumn’s Get Ready promotions designed to prepare the British public for a potential no-deal Brexit – although that was later judged to have had little impact.

Adverts featuring chief medical officer Chris Whitty telling people to remain at home have been appearing across television and radio since last week, while the the same promotion has been placed at the top of listings on Apple’s App Store and iTunes.