Civil servants, MPs and peers have returned to work in Westminster and Whitehall following yesterday’s attack on parliament.
Four people died: one police officer outside parliament, two members of the public, and the attacker, who has not yet been named.
The incident unfolded at around 2.40pm when a single attacker drove a car over Westminster Bridge, near the Houses of Parliament, killing two pedestrians and injuring at least 40 others.
The car then hit the railings outside the Houses of Parliament, where the attacker stabbed police officer Keith Palmer, who later died. The attacker was shot dead by armed officers.
How the Westminster terror attack unfolded
Following the incident, the parliamentary estate and Whitehall as put into lockdown, with civil servants locked inside departments until the early evening.
Government departments are open today with an increased security presence, including some police cordons in place around Whitehall. A one minute silence was observed at 9.33 am in Whitehall today, as well as in parliament and across the capital, to pay respect to the victims of the attack.
Prospect union deputy general secretary Garry Graham told CSW that all government departments have well-established security procedures.
“Yesterday saw a calm, orderly and proportionate response to the tragic events as they unfolded,” he said.
“Prospect is grateful to the police and emergency services for their rapid response and support. Our thoughts go out to those who were victims of the attacks yesterday and their families.”
A spokesman for the PCS trade union said: "Our thoughts are with the victims of this horrific attack and their families. We also send our solidarity to police and security staff in parliament and all those who work in and around Westminster, including MPs, their employees and civil servants."
Paying tribute to those killed and injured this morning, prime minister Theresa May said an act of terrorism had tried to silence democracy but that today parliament had met as normal.
"We are not afraid and our resolve will never waver in the face of terrorism," she told MPs in a statement.
"We meet here in the oldest of all parliaments because we know democracy and the values it entails will also prevail."