Boris Johnson will lead tributes to David Amess in parliament on Monday, as MPs told of how they felt unsafe following his murder.
The prime minister will open a Commons debate mid-afternoon which will allow MPs to speak about their former colleague. Keir Starmer is due to speak for Labour.
Tributes will follow a statement from Speaker Lindsay Hoyle and scheduled questions to home secretary Priti Patel.
On Sunday evening Amess’ family said they were “absolutely broken” after he was attacked while meeting constituents at Belfairs Methodist Church in Leigh-on-Sea, Essex, on Friday.
In a statement, the family urged people to be tolerant and “set aside hatred” as counter-terrorism officers investigate the Conservative MP’s killing.
In media interviews on Sunday, Patel said police protection for MPs at constituency meetings is among the options being considered to ensure their safety.
Andrew Rosindell, the Conservative MP for Romford, said MPs were now “a little bit” frightened. “If it could happen to David, it could happen to any MP,” he said.
Lisa Nandy also said that she did not feel safe going about her constituency. The shadow foreign secretary told the BBC’s Andrew Marr Show the murder was “heart breaking”, adding: “It does make you very anxious but none of us are going to stop doing our job as a consequence.”
Asked whether she felt safe doing her job in her constituency, the Labour MP for Wigan replied: “No, not really if I’m honest. I feel quite fortunate to have a lot constituents who are concerned about my safety.
Wes Streeting, the Labour MP for Ilford North, said politicians need to take their security more seriously.
“The uncomfortable truth that lots of us are wrestling with is that if someone wants to attack you in this way, they will do it and there is a risk that comes with this job,” he told PA Media.
“MPs are having really difficult conversations with their families this weekend about the risk that we carry, about whether it’s worth it, and what we might do to make sure that we’re keeping ourselves, our staff and our families safe.”
Writing in The Observer and the Mail on Sunday, Hoyle said he was “working closely and at pace with the Home Office and the police” to identify ways to improve MPs’ safety.
The attack came five-and-a-half years after Labour MP Jo Cox was killed by a far-right extremist in her Batley and Spen constituency in West Yorkshire.