More than 1,000 armed police will be out in force this bank holiday weekend to patrol hundreds of events across the country.
Specialist police teams have reviewed security for more than 1,300 events over the three-day weekend.
Events including the FA Cup final at Wembley and the Aviva Premiership Rugby final at Twickenham on Saturday are expected to draw thousands of people each.
Sunday’s Great Manchester Run will also go ahead, with a high number of runners and spectators expected in a show of force and defiance as the city recovers from the terror attack.
Operation Temperer, which has seen hundreds of armed soldiers support police on the streets, will be gradually wound down from midnight on Monday after the UK’s threat level was reduced from ‘critical’ to ‘severe’.
The Prime Minister has urged people to “remain vigilant”.
Police are continuing to question 11 suspects over the Manchester bombing which killed 22 people.
The attack came minutes after the end of a concert by pop star Ariana Grande, and seven children were among those who lost their lives.
Metropolitan Police Assistant Commissioner Mark Rowley, the national lead for counter-terror policing, has urged Britons to go about their business as usual over the weekend.
He said: “Enjoy yourselves and be reassured by the greater policing presence you will see.
“We can’t let the terrorists win by dissuading us from going about our normal business.”
Police have said they are making “immense” progress in their investigation of the suspected network linked to suicide bomber Salman Abedi.
Mr Rowley described some of the suspects arrested following raids in Greater Manchester, Warwickshire and Merseyside as “key players” in the terror network linked to Abedi.