Euan McColm: SNP's rising star Humza Yousaf watches his career go off the rails

Scottish Labour leader Kezia Dugdale has correctly identified Humza Yousaf as the SNPs weak point. Photograph: John Devlin

It was hardly surprising that Scotland’s rail system was in such chaos if even the minister in charge didn’t know what he was doing, went the line.

Yousaf’s remark – politically naive though it may have been – was hardly a bombshell. We should no more expect the transport minister to be expert in running a railway than we should expect the health secretary to be able to remove an appendix.

But where we should expect Yousaf to display expertise is in directing the experts who run our trains. We expect him to be in control.

Currently, it does not appear that he is.

During its time in government, the SNP has managed, by and large, to slip along without touching the sides. The party has succeeded in placing the blame for failings elsewhere while taking the credit for successes, sometimes without justification.

Conventional political scandal – and there has been a fair amount of that involving the SNP in recent years – seems to bounce off the party. But the crisis on the railways has the potential to harm the nationalists.

Passenger dissatisfaction with ScotRail has been steadily growing for months. Delays, cancelled trains and overcrowded carriages are among the things sent to try passengers. Commuters mutter darkly about the Dutch company Abellio, which currently holds the contract to run the ScotRail service.

Things reached a new low on Thursday when a broken-down train between Edinburgh’s Waverley and Haymarket stations caused chaos throughout the country. This may well have been rotten luck – apparently the train broke down at precisely the worst location it could have – but that explanation will have come as cold comfort to commuters who’ve been enduring months of bad service.

Scottish Labour’s Kezia Dugdale pursued Nicola Sturgeon on the matter during First Minister’s Questions, eliciting from the SNP leader a warning to Abellio that the Scottish Government had the right to tear up the contract.

The following day, Yousaf invited the media to watch him talk to rush-hour passengers about their experiences. Things really were that serious for the transport minister.

Yousaf, tipped by some in the party as a future SNP leader, has finally grasped that this is a vote-losing situation. When a minister invites the cameras to film him giving the impression of dynamism, we may be certain he is starting to panic.

The Tories, if they are wise, will join Labour in putting pressure on Yousaf. Right now, the transport minister represents an exposed, fleshy part of the otherwise impregnable SNP armour.

The First Minister’s threat to cancel the contract with Abellio was a smart move. Sturgeon recognises, of course, that ScotRail passengers will soon be looking for someone to blame if the service doesn’t dramatically improve and she was right to flex her muscles.

Transport minister is a stinker of a job. The incumbent is at the mercy of the elements each winter, and careless handling of a transport crisis can be deeply damaging to his career prospects. Back in 2010, the then holder of the position, Stewart Stevenson, resigned after describing the response to drivers being trapped on snow-covered motorways for more than ten hours as “first-class”. Yousaf now finds himself under the sort of pressure that Stevenson couldn’t bear.

Friday morning’s photo op may have helped Yousaf create the impression that he is on top of things but it will not make this issue go away. Passengers will expect to see swift and substantial improvements to the rail service now that the minister has begun flexing his muscles. Unfortunately, the problems with ScotRail seem to run so deep that it will take more than a few strong words from the government to get the trains back on track.

The SNP likes to paint big pictures: the First Minister and her team use bold rhetoric about a better Scotland and its place in the world. The ScotRail crisis comes as a reminder that more mundane matters can do great harm.

Dugdale has correctly identified in Yousaf the Scottish Cabinet’s weak point; for the time being, he has a sign reading “kick me” taped to the back of his jacket.

Yousaf, confident, young and approachable, has never faced anything like the crisis now dragging him down. Along with the problems he faces in reassuring commuters while fending off political attacks, Yousaf has created enemies among ScotRail staff. He could very much have done without the call from the train drivers’ union Aslef for the First Minister to sack her transport minister.

Those in the SNP who believe Yousaf is a future leader cannot have enjoyed the spectacle of his handling of this crisis so far. He has been reactive, rather than proactive. Even on Thursday morning, he was alerting commuters to the fact that ScotRail would conduct a review in order to “learn lessons”. Instead, Yousaf should have been explaining what it was that he was going to do about things. The prospect of a ScotRail review of failings by ScotRail? Really?

The test is not yet over, however, and if Yousaf can sort out the rail network then he will be hailed for his victory, and his poor performance in the early stages will be forgotten.

We will now see whether he has the political gifts required to take him, one day, to the top of the party. So far, Yousaf fails to convince.

Dugdale finds herself in the unusual position for a Labour politician of being the voice of angry voters in a row with the Scottish Government that will run and run.

Dugdale is where Ruth Davidson could have been had the Scottish Tory leader not messed up by failing to talk about trains during First Minister’s Questions.

It is not just government ministers who are tested during a crisis; opposition leaders face their own challenges.