The most famous British political ad of all time is the Saatchi & Saatchi Labour Isn’t Working poster from 1978. It showed a snaking queue of job-seekers heading towards the dole office and conveyed the dual meaning that unemployment was too high and that the government of James Callaghan was a failure.

It became folklore that this campaign helped delay the moment that ‘Sunny Jim’ went to the country. The Prime Minister subsequently became trapped by the Winter of Discontent and ended up going to the polls in May 1979. The rest, as they say, is political cliché.

This month in London, I was able to question the creators of the ad – Jeremy Sinclair and Bill Muirhead, now of M&C Saatchi – at an event to mark the 100th anniversary of the Institute of Practitioners in Advertising. I asked them whether they could have done anything to save Callaghan if he’d been the one employing them at the time rather than Margaret Thatcher.

Sinclair’s answer was a straightforward no. He thought the mood had shifted at the end of the 1970s and nothing would have rescued Labour from defeat. This was, in fact, Callaghan’s own view, as he famously talked about a ‘sea change’ in British politics.

So here’s the thing.

The most simple, successful political poster of all time – often credited with handing the election to Margaret Thatcher – didn’t actually make a huge difference at all. She would have won anyway.

And this was the circle we endlessly tried to square during the meeting at the British Academy, which was also attended by Shawn Woodward (the former MP who sat on both sides of the House) and the tough-as-nails Lord Tebbit – hardline cabinet minister in Margaret Thatcher’s government.

The two politicians were adamant that without a ‘product’, no amount of advertising did any good. And yet here we all were, looking at a load of great hard-hitting ads.

In 1992, Saatchi launched the Double Whammy and Labour’s Tax Bombshell posters. They spoke to underlying concern that Labour had not costed its programme properly. And as Kinnock had ruled out more borrowing, that could only mean one thing: taxation.

Muirhead revealed that they’d taken some figure from Conservative Central Office about the total cost of Labour’s plans and divided it by the number of taxpayers in the country to give a nice round number for the bombshell.  Last year’s Brexit campaign brought its own dubious round figures, of course, on the sides of buses.

We saw my favourite of all the ads, which dates from the 1987 campaign. A British soldier is shown with his hands aloft in surrender. The devastating headline read: Labour’s Policy on Arms.  They could run that one in 2020 if Corbyn is still in charge. Tebbit revealed an even harder-hitting one that never hit the streets. It showed a Russian bomber in flight with its doors open and a headline which read: If we dropped our weapons, would the Russians drop theirs?

But once again, according to Thatcher’s right-hand man, the 1987 election was never in doubt. And this was despite the fact Tebbit recalls Lord Young grabbing him by the lapel in a confrontation barely short of fisticuffs and yelling that they were going to ‘f***ing lose’!

My sense from listening to discussion as a whole is that political advertising works best when it’s simple, straightforward and speaks to an essential truth that people may already believe. Actually, from my experience in the industry, that’s how all advertising works best.

If you try to sell people an idea they don’t already suspect to be true, it bounces. The most obvious example is the New Labour, New Danger campaign about Tony Blair. The attacks on Labour had run out of steam by that point and nothing short of a miracle was going to see the Tories elected for a fifth term in 1997. So the campaign may have looked clever and effective and ticked all the boxes. But it lacked resonance.

Two other tips worth bearing in mind.

First of all, don’t be unfair to people. When M&C Saatchi showed mocked-up visuals of Ed Miliband struggling with armbands in the deep end of a pool, voters reacted badly. They thought it was hurtful.  When Alex Salmond was added at the side of the pool, looking on calmly, the message hit home.  That was the germ of the idea for the posters showing Red Ed in the Scotsman’s pocket.

The second point is not to view the ads through a metropolitan prism. Yes, it’s the old issue of the ‘urban elite’. Journalists and columnists raved over Kinnock The Movie in 1997, shot by Hugh Hudson. They were scathing and patronising, however, about the 1992 film of John Major making his way back to his childhood home in Brixton.

‘Is it still there?’

‘It is!’

As we know, Kinnock lost both elections.

At the end of the talk, someone had to ask the panel about Jez of course.

Shaun Woodward summed it up pretty well, by turning to the advertising guys on the top table and saying: ‘These guys are good, but they’re not miracle workers!’

Phil Woodford

Phil Woodford stood on two occasions as a Labour Parliamentary candidate and is a former chair of Holborn & St Pancras CLP. He currently works as a writer, trainer and lecturer and co-hosts a weekly news review show on London's Colourful Radio.