‘United in shock’ - our political editor Annabelle Dickson on how Westminster reacted as terrorist tragedy in London unfolded

Police outside the Palace of Westminster, London. Picture: Jonathan Brady/PA

Police outside the Palace of Westminster, London. Picture: Jonathan Brady/PA - Credit: PA

Like the famous green benches of the House of Commons, the police are part of the fabric of Westminster.

Police outside the Palace of Westminster. Photo: Victoria Jones/PA Wire

Police outside the Palace of Westminster. Photo: Victoria Jones/PA Wire - Credit: PA

Leave work late at night and a policeman will cheerily bid you farewell, still posing for tourist photographs at the famous Carriage Gates with a Big Ben backdrop.

In the morning, they meticulously watch over the hundreds of workers who toil in the historic Houses of Parliament.

For years, the building has been on the highest security alert. The message was that it was a matter of when, not if, we would come under attack.

Many staff had drifted back to their offices after lunch, MPs were on their way to vote, rushing down the famous colonnades. It was as normal a Wednesday afternoon as you can get in the Palace of Westminster.

But the ins and outs of Brexit, verdicts on prime minister's questions and the issues of school funding began to seem inconsequential as it became evident multiple lives had been lost.

It all began with a loud bang – a car crashing into a wall. Journalists were roused from their desk. The gun shots came later.

Most Read

The rolling news quickly told those in lockdown of the Westminster Bridge bloodbath which had preceded our own attack.

Under one window of our office, people were frantically trying to save the life of a policeman - to no avail.

It later transpired an MP was among the rescue team.

If you strained your eyes from the window, you could see the car which had mounted the pavement.

Squat teams of police sprinted across New Palace Yard – a place where you usually see MPs and other workers laughing and joking as they trot across the cobbles.

The prospect of an attacker on the loose suddenly felt far too real.

We were told to go nowhere.

The press gallery of the House of Commons chamber – where MPs were locked in for safety – was even out of bounds. The danger was real.

And it became clear pretty quickly that the attacker had claimed victims.

Blood-stained police could be seen in the vicinity of our offices. Their colleagues eventually ushered us into Westminster Hall, hoping to find witnesses and footage which will help them to make sense of the horrific few hours.

From caterers to researchers to clerks and peers, those who keep our democracy running on a daily basis sat side-by-side waiting for news.

The mood was subdued as thoughts turned to the policeman who gave his life to protect us.

He was a fellow Westminster worker.

Just moments before his life was so cruelly taken he might have posed for a picture with a tourist, greeted an MP arriving back to vote or been in the canteen having a tea break.

Westminster is a close-knit community for good and ill and yesterday, it united in shock.

But it was also full of thanks to a man who was the front line against attack and gave his life to protect others.