Sir David Amess' murder, described by Home Secretary Priti Patel as a "attack on democracy," raises new concerns about the safety of MPs.
In his Southend West constituency surgery, Sir David, 69, was fatally stabbed, and Patel expressed shock and sadness.
Five and a half years earlier, a far-right fanatic assassinated Labour MP Jo Cox in her West Yorkshire seat of Batley and Spen.
The loss of "kind and faithful friend" Patel, she claimed, had "devastated" her.
I have no words to express how heartbreaking it is that he was slain while performing his duty as a member of Congress. In a series of tweets, she called it "a senseless attack on democracy itself."
The safety of our country's elected officials is a legitimate concern, and I will offer updates when appropriate.
MP security must be reexamined, according to Speaker of the House Sir Lindsay Hoyle. Hoyle described himself as "shocked and genuinely troubled" by the incident.
There will be ripple effects throughout the parliamentary community and the entire country, according to him.
For the time being, our thoughts and prayers are with David's family, friends, and colleagues. We will review and examine MPs' security and any measures to be made in the following days.
The longest-serving MP in Westminster, Sir Peter Bottomley, said MPs will want to continue meeting their constituents in person despite the sense of shock and loss in Westminster.
This weekend, next weekend, and in the months to come, MPs will hold advising sessions across the country, according to what I foresee. That's exactly what we do here at the firm. He told the PA news agency that "when there is a challenge, we have to face it."
"No one can have complete security. In many other professions, you face considerably more dangers than as a member of parliament, in my opinion.
"Members of Parliament may be the subject of extensive media coverage. We can't say that we're unique in any way. We're just regular folks trying to do our best in a regular job. We are aware of the dangers and are willing to embrace them.
Being a member of Parliament necessitates effort and vigilance. I expect local police to meet with members of parliament.
There is a debate about whether or not MPs should discontinue meeting with their constituents in person. We will continue to meet with our constituents in person, is the answer.
"We are frequently the last persons they turn to when they are in dire straits," says the pastor. "Their wants and needs come first.
The attack on Sir David echoed two other events in which MPs were attacked in their areas, including the death of Jo Cox in June 2016, just days before the Brexit referendum.
Islamic terrorist Roshonara Choudhry, who stabbed East Ham MP Stephen Timms twice in the abdomen, claimed she had done it "to achieve retribution for the people of Iraq." in May 2010.
Timms was critically injured and was "very fortunate not to have been killed," according to authorities. He's still a member of Parliament.
In January 2000, a man brandished a sword at Nigel Jones, MP for Cheltenham, inflicting serious injuries.
While attempting to defend the then-MP, Gloucestershire county councillor Andrew Pennington was assassinated in the same attack.
The George Medal for valour was presented to him after his death.