Given that the week started with the expectation of blue-on-blue combat over the EU Withdrawal Bill (largely averted via a compromise with Dominic Grieve), it’s a bit surprising that it’s featured a seemingly growing wave of red-on-red infighting over Brexit among the Opposition.

First we had the protest by pro-EU activists claiming to be Labour members at LabourLive, who unfurled a banner criticising Jeremy Corbyn for what they view as supporting Brexit. The Labour MEPs’ group stall at the same event also took the opportunity to critique the Labour leader’s policy, being manned by Seb Dance MEP, resplendent in a “Bollocks to Brexit” sticker and “Stop Brexit” t-shirt.

The Corbynites weren’t slow to return fire. Skwawkbox, the slavishly loyal blog, dug into the “problematic history” of the founders of ‘Our Future Our Choice’ (OFOC), the campaign group responsible, disputed the protesters’ claim to have been thrown out of the event, accused them of “entitled and arrogant” behaviour to other audience members, and carefully noted their links to the Blairite group Progress.

Aaron Bastani, founder of Novara Media, the other pillar of cyber-Corbynism, took on OFOC on the Daily Politics, justifying their expulsion on the grounds of “causing a public nuisance”, accusing the group of being “used by elite interests” like Alastair Campbell and Lord Mandelson, and pointing to their Westminster offices as something that should cast their claim to grassroots status into doubt. An attack video put out by Bastani criticsed OFOC as “not progressives, they are not on the side of real change” who “want business as usual, by and for the elite”, and featured a list of the peers of the realm who support their sponsors.

Owen Jones, who has somehow managed to simultaneously switch away from Euroscepticism but towards Corbynism mocked OFOC on Twitter for their faith in Conservative would-be rebels, while former Corbyn adviser Matt Zarb-Cousin criticised “continuity Remain” for “a giant expensive whinge[,] mainly at Corbyn”. The Morning Star ran an investigation into “the big money, lobbyists and Blairites behind Stop Brexit outfits” whom it concluded “seem happier attacking Corbyn’s Labour with phoney, paid-for PR campaigns than attacking the actual government carrying out Brexit.”

The Labour Party’s hardcore Remainers didn’t fall silent after Saturday’s protest. On Monday they launched attack posters portraying John McDonnell tucked into Jacob Rees-Mogg’s top pocket (“as if he was a patsy for the powerful”, Bastani complained). Other EU enthusiasts rallied round, with the well-funded campaigning barrister Jolyon Maugham describing Novara’s attitude towards OFOC as “smug, patronising…Brocialism at its most unattractive.”

The infighting wasn’t confined to Corbynite and pro-EU campaigners and bloggers – it reached the Shadow Cabinet and the Parliamentary Labour Party. Emily Thornberry, the Shadow Foreign Secretary, used her speech at yesterday’s Press Gallery lunch to mount an extraordinary attack on Chuka Umunna and other MPs who had rebelled in favour of the EEA, saying “their real driving mission is simply to reverse the democratic decision of the referendum…if that’s how you feel, why not be honest and simply say so rather than waste everyone’s time”.

Umunna did not take the criticism well, and responded bluntly: “I don’t think accusing a whole bunch of your parliamentary colleagues of being dishonest, and insulting and patronising them for sticking up for what they believe is best for their communities, is very diplomatic behaviour for a possible future foreign secretary. It makes a good headline but is not a great look.”

The Government still has no majority, and a variety of problems – including the fact that some of the complaints of those who threatened to rebel this week have been postponed rather than neutralised – but it is quite remarkable to see the Opposition somehow managing to look the more divided of the two. Labour’s tribal civil war, underway since before Corbyn’s first election as leader, is far from over, and Brexit has become a hotly-contested front in that conflict. Expect things to get more bitter before they get less so.