The Palace of Westminster has been closed to non-passholders today, in the wake of Monday night's terror attack in Manchester.
This means all tours, events and banqueting will be cancelled with immediate effect. This arrangement will remain in place until the advice changes, the government said.
Police advised that the Palace of Westminster should be closed today, after Prime Minister Theresa May last night said the terror threat to the UK had risen from severe to critical. Troops have been deployed throughout the UK today in response to the increased threat, in order to support the police with their operations.
Meanwhile, the Ministry of Defence confirmed that today's Changing of the Guard ceremony at Buckingham Palace has been cancelled in order to redeploy police officers.
On Monday night 22 people were killed by a terrorist at a concert in Manchester.
Greater Manchester chief constable Ian Hopkins revealed the identity of the suicide bomber as 22-year-old Salman Abedi. Islamic State has claimed responsibility for the atrocity.