The UK Metropolitan Police will carry out the UK's biggest counter-terror exercise.
SAS soldiers and 400 regular troupes will take part in Operation Strong Tower; a drill to test the response to a major terrorist attacks.
A number of suspected accomplices have been arrested over the Tunisia terror attacks and the Government's crisis response committee, COBRA, meets today.
There will be a national minute of silence on Friday at 12pm.
Prime Minister, David Cameron said, "together we will prevail" against terror.
From the terror in Tunisia has emerged tales of heroism, bravery and survival.
Paul Short has been described as a hero after running into the gun fire to help a man who was bleeding to death.
Paul and wife Sarah are now safely home in Northumberland.
Paul said, "I didn't even ask him his name, I was that concerned that he was bleeding... the gunman was just around the corner, not even 50 meters from us."
No no no, this guy only has 27 lines! I don't want to go backwards with my career. I want to be a hero!
But as the Terminator makes it's return, Arnold Schwarzenegger tells us that he wasn't originally the main man for the role.
Arnie's most famous line, "I'll be back", is the most quoted line in movie history but that almost didn't go to plan either. Arnie said, "When I said it, I felt it did sound strong enough. I thought it would be more machine-like to say, 'I will be back'. James Cameron said, 'no... what does the script say... stick to what I wrote."
Terminator Genisys is in cinemas from 2 July.
Today we'll see fine, dry and humid conditions. It'll be hot by day but the night time conditions will be oppressive.
There will be a little cloud across the west with the chance of a little rain.
Low 20s in the north, mid to high 20s in the south with very high pollen levels and UV.
The Education Secretary, Nicky Morgan, tells schools "satisfactory is not good enough" when it comes to grades.
Secondary schools who repeated fail to ensure that less than 60% of pupils fail to get 5 A-C GCSEs will be ordered to improve.
Nicky Morgan will warn that any school classed as 'coasting' will have three years to improve or face becoming an academy.
Four British tourists seriously wounded in the Tunisian massacre have returned to home soil.
An RAF jet touched down in the early hours of this morning in Birmingham and then Brize Norton.
Some of the injured are being treated at the Queen Elizabeth Hospital in Birmingham.
The Met Office has issued a health warning as temperatures are predicted to reach mid-30s on Wednesday.
High temperatures caused by hot plume of air from Africa and Britain is expected to be hotter than Brazil and Florida.
Public Health England advise people to try to stay out of the sun between 11am and 3pm and for vulnerable people to stay indoors.