Cabinet reshuffle: Where did it go wrong for Gavin Williamson?

Gavin Williamson has been the highest-profile education secretary for England since Michael Gove - but probably not for the right reasons.

If the pandemic had a political fall guy, it was always likely to be Mr Williamson - often the lightning rod for irritation and exasperation from families facing disruption and seeing U-turns on schools and exams.

He has now tweeted his departure - but it is still not clear if he will be offered another post.

It might seem a long time ago now, but before the pandemic Mr Williamson was seen as the bringer of good news.

His predecessors as education secretary had faced constant maulings over school funding shortages - but Mr Williamson arrived with the promise of a £7bn increase. It was big bucks and big ambitions.

The trouble only really began when his department collided with the giant iceberg of Covid.

The first dent was a major U-turn on getting all primary school pupils back to school, and then there were self-defeating battles with Marcus Rashford over free meals in the holidays.

Online learning at home tested parents' patience and fed into worries about lost learning and annoyance at the hokey-cokey of going in and out of school, with hundreds of thousands of pupils regularly having to isolate.

But the biggest disaster was the chaos of last year's exams, with multiple U-turns and late-night lurches in policy that saw grades go through the roof and his department's most senior civil servant and the head of the exams watchdog both go out the door.

That such senior staff had to step down while he stayed put didn't add to the lustre of his reputation.

There has never been a full independent inquiry into what went wrong with the 2020 exams - so it's hard to know who was really to blame. But it did serious harm to Mr Williamson's credibility - and there was no shortage of people on his own side who were privately ready to point the finger.

And his poll ratings among Conservative supporters remained resolutely negative.

As a former chief whip, it was said his survival chances were boosted by knowing where the bodies were buried. But he also made political enemies ready to come back to haunt him.

Mr Williamson, who has never appeared to complain about the criticism directed at him, could also feel aggrieved that he was taking the blame for decisions that were never down to an individual minister.

That was encapsulated in the plans to get schools back in January 2021, when his determination to open classrooms was reversed almost immediately by another lockdown.

The education secretary doesn't write the cheques but he was left holding a punctured balloon of a policy.

This year's replacement exam results, with much responsibility outsourced to teachers and schools, didn't have any of the major problems of last year. There would have been cause for quiet celebration that it had all gone relatively smoothly - not an easy achievement in what remain unprecedented circumstances.

It's hard to know what the legacy will be of his education plans, because he never really got a chance to start them, beyond pushing for a greater emphasis on skills and further education. The pandemic overshadowed everything else.

Will he bounce back to a big post in government again? At 45 he is still young by political standards, and has the northern, state-school, non-Oxbridge credentials for the government's levelling up plans.

He certainly seems ready to fight on, describing himself as having the hide of a rhino.

"Not every day has been brilliant," he told them.