Terror came on Wednesday to the seat of government and Parliament for the first time since the IRA attacked Downing Street with mortar fire in 1991. Prior to that, in 1979 Airey Neave MP was murdered by a bomb planted in his vehicle which went off in the House of Commons car park. This time, people walking on Westminster Bridge were mown down by a car whose driver then proceeded to Parliament.

The assailant rushed the officers on the gate and was able to assault and kill a policeman before being shot dead. Praise must go to the officers who stopped him going any further and to the emergency services who were quickly on the scene to tend to the dead and injured.

All such attacks are appalling but especially so when the democratic process is the target and innocent people simply taking in the sights are the victims. Partly as a result of those earlier atrocities the security around the Palace of Westminster is nowadays extremely tight while allowing life to go on as normally as possible. But the days when it was permissible to move easily around government buildings – or even walk through Downing Street from Whitehall to St James’s Park unchallenged – have long gone.