Britons need to get to know their neighbours, a former Downing Street advisor has said, as he launched a campaign to encourage people to connect in real life.
Max Chambers says social media has allowed people to "live in a bubble" with people they already know.
But he wants them to "share a cuppa" with someone in their area in August.
It comes after a survey suggests 60% of people do not know their neighbours well or at all.
Mr Chamber's social network Nextdoor has teamed up with Neighbourhood Watch and a charity called The Challenge to call on the government to create an official national Good Neighbours Day in 2018.
Do you have a good neighbour? Do you feel you can rely on them in time of need? Tell us your stories by emailing email@example.com or get in touch on WhatsApp 07555 173285.
They want it to be a follow-up to the Great Get Together - organised by Brendan Cox in memory of murdered Labour MP Jo Cox.
A survey of 2,000 people commissioned by Nextdoor suggests some 75% of people say they would not want their neighbour to look after their pet while on holiday.
Almost two-thirds of people said they would not feel confident leaving a spare key with their neighbour.
Mr Chambers warned that the internet meant people were "losing touch with those immediately around us".
Some 63% said they never borrowed something or exchanged favours with the people next door.
Speaking on BBC Radio West Midlands, he said: "Organisations like Facebook and Twitter allow us to live in a bubble with people we already know maybe that we went to school with or know through work.
"It's meaning we're interacting with different kinds of people less and less."
Asked what his former role with counter-terrorism had to do with communities, Mr Chambers said he had seen first hand the UK becoming less integrated.
Dame Louise Casey, government advisor on social integration, said recent events like the Grenfell Tower fire had shown "how powerful the public can be when we pull together, united in the common good to protect and care for each other".
"Government and public services will always have a role in this but it is the public, residents and families, first and foremost who are in the best position to knit that social fabric together."
How friendly is your area?
- The West Midlands is the most neighbourly area in the UK with 59% saying they feel very or somewhat connected to their neighbourhood.
- Wales, Yorkshire and the West Midlands are the regions where people are most friendly with their neighbours
- People in Northern Ireland and Scotland feel the most lonely in the communities they live in.
- Londoners are least likely to know the names of their neighbours.
- The place most unlikely to give a spare key to a neighbour, borrow some sugar, babysit or look after a pet was north-east England