Theresa May has now signed a letter to trigger Article 50, the start of the official process to leave the EU.
Safety Warning After Beach Deaths
Following a deadly weekend on British beaches, the RNLI has urged seaside visitors to respect the water as warm weather approaches.
Six people including a woman and her six-year-old son died in a series of tragedies that hit the nation's coasts as unseasonably stormy weather blew in.
Meanwhile, more than £22,000 has since been donated to the family of a gardener who was swept to his death from Fistral Beach in Cornwall on Saturday.
Rudy Bruynius, who has been named online, was with wife Lisinda and their two-year-old daughter McKayla when they were caught by a large wave at Fistral Beach on the north-west coast of Cornwall.
With a spell of hot weather expected to see temperatures climb to 30C (86F) midweek - and fine weather forecast for the start of the bank holiday - the RNLI repeated warnings for those heading to the seaside.
A spokeswoman said: "With the weather due to get warmer and the bank holiday ahead, the RNLI would urge people to take care when near the coast and respect the water.
"The sea may look appealing, and the RNLI would encourage people to use it, but do so safely - it can be dangerously unpredictable.
"Please visit lifeguarded beaches and swim between the red and yellow flags - the safe swim zone and the area watched by lifeguards.
"RNLI lifeguards are always happy to answer any questions or advise of any risks, including where any rip currents may be, which can catch out even the most experienced swimmers.''
The appeal comes after three men, two women and a young child died in separate incidents on Saturday amid strong winds and stormy conditions over the weekend.
A mother and son, who have been named by police as Julie Walker, 37, and Lucas Walker, six, died in hospital after a rescue operation at Aberdeen beach.
A total of five people were pulled from the water and taken to Aberdeen Royal Infirmary.
Lucas's brother, Samuel, who bravely entered the water in an attempt to save his mother and brother, is making a ``steady recovery'' in hospital, police said.
In Cornwall, Mr Bruynius, who was originally from South Africa but was living in London, was taken to hospital where he was pronounced dead, while McKayla was reported to be in a critical condition.
Two other children in the family managed to scramble back on to the rocks, the RNLI said.
A fundraising page, set up to support the family, saw a stream of donations when news of the deaths emerged.
Family friend Madelein Jansen Van Noordwyk posted a message from Mrs Bruynius which said: ``Thank you all so much for your prayers!!!''
Joy Godfray was a day away from her 32nd birthday when she died in hospital after getting into difficulty while swimming off Green Island in Jersey at around 8.30pm.
A man swimming with Ms Godfray was pulled to safety by members of the public.
The States of Jersey Police said her family, who do not wish to speak about the death, want to pass their ``heartfelt thanks to the members of the public and all the emergency services who fought to save the life of their daughter''.
A 67-year-old man reportedly died while surfing off the West Mersea coast in Essex. The man, named locally as David Baker, of Colchester, Essex, was said to have been an experienced surfer.
A sixth victim, believed to be in his 50s, died after getting into trouble outside the safe swim area at Sandbanks beach in Poole, Dorset, at around 3.30pm.
The victim, who has not been named, was seen having difficulty in the rip current. He was recovered from the water by lifeguards who performed CPR and an air ambulance and paramedics attended, but the man, believed to be in his 50s, was pronounced dead at the scene.
On Tuesday temperatures are expected to reach 25C (77F) along the coast of East Anglia and Essex and 23C (73F) in Cornwall.
The mercury is forecast to rise up to 28C (82F) along the Kent coast on Wednesday, although it will be cooler in the West.
The consumption of Dunsyre Blue cheese was the source of a fatal E.coli outbreak last year, an investigation has concluded.
A driver tried to mow down a police officer in an attempted murder in Glasgow.
Inspectors found two patient trolleys "heavily contaminated with blood and faeces'' on a visit to Scotland's newest hospital.
Most Viewed Pictures On Heart
Recently Played Tracks
To listen live, choose your preferred station:
Now playing: Non-stop hit music
Deposit £10 to get a £40 Welcome Bonus - That's £50 to play bingo, slots and more!*
Over 50 tracks to make you feel-good. New album out now...
Find your local four day weather report here.
Make Heart the soundtrack to your day and you could be a winner with great prizes up for grabs throughout the day.
Find out more about some of the companies advertising on Heart Scotland- East.