Retweet "to spread the word", Tory party chairman Grant Shapps asked of Twitter; and boy did Twitter deliver. The good news, a twitchy adviser could have told him, is that the Tories' post-budget poster has gone viral in a way that few political posters ever do. The small caveat, they may justifiably have added, is it may have trashed the budget, fuelled a growing Tory civil war and reinforced a toxic image of the Conservatives that is lethal to the party's electoral prospects. Whoops.

It is difficult to know where to begin with this poster: it is an #epicfail, to use the appropriate Twitter lingo. The suggestion that cutting bingo tax and beer duty will "help hardworking people do more of the things they enjoy" is so patronising it looks like a crude attempt at satire: indeed, the only comfort on offer for the Tories is that some social media users genuinely believed it was a parody. The fatal pronoun is "they": it looks like a conscious attempt by well-heeled Tories to distance themselves from the great unwashed, who are presumably all getting hammered in bingo halls. This is the real "plebgate".

Within minutes the parodies were emerging. "I say, you there! How is your whippet? Jolly good, jolly good. Carry on," offered Edinburgh's Duncan Hothersall. The famous Tory poster from 1992 featuring John Major was suitably amended: "What does the Conservative party offer a working class kid from Brixton? Beer and bingo."

Desperate Tory spinners – who are no doubt currently taking it in turns to rock in the foetal position – are hoping to portray this as a smear campaign from a Labour party stung by a weak response to the budget. I doubt the likes of the Daily Mail's Tim Shipman could be portrayed as Ed Miliband outriders, though: "Could this Tory ad be any worse, even if it said: 'Dance, drink and screw, because there's nothing else to do?'" he asked.

As far as Twitter is concerned, the election campaign is well and truly on. But this incident is potentially far more significant than being the mother of all Twitter storms. British workers have suffered the longest fall in living standards since the 1870s, and the Tory offer is making pints of beer 1p cheaper and cutting bingo tax. Oh, and the Bingo Association has pointed out that reducing duty of bingo hall profits from 20% to 10% will have "no money-in-the-pocket effect for customers", so let's park that in the "patronising and irrelevant" box.

According to the polls, over half of the population believe that the Tories only represent the interests of the rich. The cabinet is dominated by white, privately educated men, the sort of government that would not look out of place in 19th century Britain. Every time they have won an election since 1955 has been on a lower share of the vote than the time before, and they have not been victorious since 1992: and it is the death of working-class Toryism that is largely responsible. The Tories used to win in Scotland and cities such as Liverpool. Admittedly, this was helped by religious sectarian divisions, but they used to win in Manchester, Sheffield and the north-east, too. The more they look like braying upper-class snobs with contempt for ordinary people, the more doomed they are.

Some Tories are all too aware of this looming existential crisis. When Norman Tebbit is slamming the "bedroom tax" for damaging the Tories' election hopes, it's time for a rethink. Michael Gove's attack on the "preposterous" number of old Etonians at the top was clearly a bit of political positioning, but it taps into a problem acknowledged by sensible Tories. The same goes for Baroness Warsi – one of the few senior Tories who is either a woman or from an ethnic minority background – when she held up a spoof newspaper slamming an "Eton mess" on ITV's The Agenda. Unless she is listened to, and the party tries to resurrect a dying breed of working-class Toryism that relates to people's everyday issues and concerns, the party is toast.

Outside of the leadership, there are sensible voices such as David Skelton and his Renewal group, who are actively trying to rebuild a Toryism that is attractive to working-class people and northerners. They will have sore heads this morning: not from overdoing the beer and bingo, but from slamming their heads against tables. There is little sign they are being listened to. If Labour HQ's prayers are answered, they will remain on the sidelines.