Hello. Here's your morning briefing:
Experts to test Salisbury nerve agent
A team of international experts is due to arrive in the UK to assess the nerve agent used to poison ex-spy Sergei Skripal and his daughter Yulia in Salisbury. The Organisation for the Prohibition of Chemical Weapons delegation will visit the military research base at Porton Down in Wiltshire, whose own experts say the agent is of a type first developed by Russia.
Foreign Secretary Boris Johnson has accused Moscow of stockpiling the agent used. But President Vladimir Putin said Russia had destroyed all of its chemical weapons and it was "nonsense" to implicate his government in the attack on 4 March.
Mr and Ms Skripal remain critically ill in hospital. Here's what we know so far.
Putin remains as Russian president
Vladimir Putin has won again, as widely expected. He's been re-elected as Russian president with an increased - 76% - share of the vote and will remain in office for another six years. Asked about running again in 2024, he replied: "What you are saying is a bit funny. Do you think that I will stay here until I'm 100 years old? No!"
His win means Mr Putin will have been either Russian president or prime minister for 24 years. His nearest rival, millionaire communist Pavel Grudinin, got 12% of the vote. But main opposition leader Alexei Navalny, was barred from running.
Independent election monitoring group Golos reported hundreds of irregularities on polling day - including some papers being found in boxes before voting started and webcams at some polling stations being obstructed by balloons and other objects. But the head of Russia's Central Electoral Commission said there had been no serious violations. Here's a profile of Mr Putin.
TV's Ant McPartlin in drink-driving arrest
Ant McPartlin, co-host of TV shows Britain's Got Talent and I'm A Celebrity, has been arrested on suspicion of drink-driving following a collision involving three vehicles. Police were called to the scene in Mortlake, south-west London, on Sunday afternoon. Ambulance staff treated a number of people for minor injuries.
Drivers stranded in heavy snow
The so-called "mini-Beast from the East" has indeed not been as powerful as its predecessor, but it's still brought disruption. A Met Office yellow warning for ice is in place for most of England and Wales, central and southern Scotland and parts of Northern Ireland until 10:00 GMT. And dozens of vehicles have been stranded on the A30 dual carriageway in Devon. Forecasters say more normal, spring-like conditions will return by Tuesday.
What are the UK's oldest and youngest city populations?
By Andrew Carter and Paul Swinney, Centre for Cities
Over the past two decades, the average age of a UK resident has risen by two years, to 40. Within 30 years, one in four people is expected to be aged 65 and over. But the picture in cities is more complex. At 38, the average city dweller is younger. Cities are home to 62% of people aged 18-34, but only 46% of those aged 65 and over. Despite this, the populations of most UK cities are growing older, raising big questions about what that means for their development, and for meeting the future needs of residents.
What the papers say
The Guardian leads on the alleged information breach involving 50 million Facebook profiles, while the Financial Times says politicians are calling for a more detailed response from the social media giant. Meanwhile, the i calls Valdimir Putin's election win a "landslide" - and reports on the Russian president dismissing allegations that his country was behind the Salisbury poisonings as "nonsense". And the Daily Mail warns that food on sale in supermarkets is widely tainted with airborne plastic particles.
Stem cell transplant "Game changer" for multiple sclerosis patients
Martina Navratilova BBC pays John McEnroe far more than me, says tennis star
Circus death Cirque du Soleil aerialist falls on to stage during Florida show
Australia bushfire Dozens of buildings feared lost in coastal town of Tathra
If you see one thing today
If you listen to one thing today
If you read one thing today
14:30 ParalympicsGB athletes are due to land at Heathrow Airport, as they return from Pyeongchang, South Korea.
18:40 US President Donald Trump is expected to unveil a plan to combat the opioid crisis, including urging prosecutors to seek the death penalty for drug dealers in fatal overdose cases.
On this day
1976 Princess Margaret and Lord Snowdon are to separate after 16 years of marriage, Buckingham Palace announces.