This week saw one of the season’s most exciting football matches end in bitter controversy as a video refereeing decision denied Manchester City the goal that would have taken them through to the Champions League semi-finals.

A few miles down the East Lancs Road at the UK’s biggest teaching union’s conference in Liverpool, technology decided the outcome of another tightly contested drama - whether or not NEU teaching union members should be balloted for a national boycott of Sats.

And the prize for many of the delegates was every bit as sought after as reaching the penultimate stage of club football’s most prestigious competition. For some NEU activists, the chance to vote to take action against national testing was seen as an opportunity to begin the end one of the most teacher-hated policies in England’s schools.

That helps to explain why the finish of Monday’s Sats debate at the NEU conference became just as fraught and close as Man City’s rollercoaster 4-4 cup tie with Spurs.

Quick read: Teachers to be balloted on Sats boycott

Last year: NEU leader’s ‘moral case’ for refusing to do damaging tests

2018 Sats: 64 per cent of pupils pass three Rs

The vote for a ballot among 1,600 union delegates had initially been called as lost based on joint-president Kiri Tunks counting the number of delegates holding up their agendas. And by sight, it did look like an extremely close call, with much dismay at her ruling.

Ms Tunks then asked for another show of agendas, yet still reached the same conclusion - only to be confronted with football-style chants calling for a “digi vote” using digital handsets - the NEU’s equivalent of football’s VAR (video assistant referee).  

But Tunks repeated her decision that it had been lost and asked delegates to be quiet. You got the feeling half the hall were about to walk out in frustration, not least because of memories of past grievances. Duncan Morrison, of the NEU’s Lewisham branch who moved the motion, had already claimed that calls for a boycott had been “manipulated” at previous conferences.

The complaints continued. One delegate took the mic and said Tunks had miscounted because of poor lighting, while another said it was “discrimination” that wheelchair users couldn’t stand up to be part of the 200 people needed to stand up so there’d be another count.

But that number was soon reached, prompting another count - this time by digital vote - which backed a boycott ballot by 56 per cent against 43 per cent.

So the less cautious of the NEU’s anti-Sats campaigners had what they wanted - suggestions of a more gradual strategy have been thrown to the wind and the union will now go full steam ahead to ballot nearly half million members over a national Sats boycott. 

But you wonder how successful that ballot might be given that it’s been tried before and that for any actual boycott to take place, by law, the ballot needs to have at least a 50 per cent turnout.

The cause might be helped, of course, by the attention Labour leader Jeremy Corbyn, has given to it. He turned up at the NEU’s conference the following day pledging to ban Sats if Labour were elected to office. Mr Corbyn spoke of the “regime of extreme pressure testing” which was giving young children nightmares and leaving them in floods of tears in a speech that made plenty of national headlines.

Nevertheless, progress towards an actual boycott is, as North Yorkshire headteacher and former NEU president Anne Swift admitted when I spoke to her in Liverpool, not necessarily straightforward.

“We need headteachers on board,” she said. “It’s very difficult for teachers to turn around to their heads and say we’re not doing Sats - because it’ll make them vulnerable. But if we have the heads on board, then I think we’ve got a chance.”  

So just as beating Man City will not guarantee that Spurs can beat Ajax in the next round to reach the Champion’s League final, so the NEU’s anti-SATs vanguard should be very wary of taking a national boycott for granted.