Labour MPs have been sent threatening emails, faced crowds of protesters gathering outside their house, and even had their own councillors call for them to be deselected if they vote in favour of airstrikes in Syria today.
Hull North MP Diana Johnson has received an email saying those who voted in favour of the government's plan would face lobbying to secure a vote of no confidence six months on from today.
"If the vote of no confidence is carried the MPs can then limp on until their selection at the next General Election, when they will be deselected," the email said. "During the four year period in the run up to the next General Election, the whole country will now [sic] of the no confidence in thr MPs from their Labour party."
Labour party members would "try to wash the blood from their hands of the innocent civilians which the bombs will surely kill". the email added.
Posting on her Facebook page, Johnson said she was "very saddened" to have received the message, saying she had spent the last few days consulting with constituents "and considering in detail the evidence and proposals from the government".
It is claimed that the email has been sent to other MPs as well.
Last night hundreds of people descended on Parliament Square to protest against bombing Syria. Some protesters even made their way to Walthamstow Labour MP Stella Creasy's house, noting "she has no children to upset".
New politics... pic.twitter.com/ynM86dh0W5— Ben (@Jamin2g) December 2, 2015
Meanwhile Asim Mahmood, a Labour councillor in Walthamstow, has called for any MP who supports the vote should "automatically go through a trigger ballot for reselection".
Creasy said in a Facebook post that she would not "be bullied by a sitting Walthamstow Labour councillor with the threat of deselection if I don't do what he wants".
"On a matter of national security, such intimidation is completely unacceptable and disrespectful to the residents of Walthamstow who deserve better and glad to hear Jeremy in PLP condemn such conduct."
Labour leader Jeremy Corbyn has come under fire from some on the left for allowing his MPs a free vote, although he has said he will vote against the airstrikes.
Yesterday the party was reportedly forced to cancel a phone canvassing event in support of Oldham candidate Jim McMahon because Stop the War was planning to march on Labour's Brewers Green HQ in protest against his decision.
David Cameron has fuelled the fire further when he reportedly urged MPs not to be swayed by "Jeremy Corbyn and a bunch of terrorist sympathisers".
Thousands of people on Twitter have been appropriating the hashtag #Terroristsympathiser in response.
Update: Demonstrators in Walthamstow have since said that the protest was a peaceful candlelight vigil, held outside Creasy's office rather than her home, and that the man who posted about the MP's children had nothing to do with them.