Why does the NEU say that teachers should not be expected to mark work during the pandemic?

[Thenagainmaybenot]

The national education union says that:
'Worksheets and textbook pages for maths and English can work if they are already used in school and all children have them at home. However, teachers cannot be expected to mark work. Schools should not be setting SATs tests or mocks at this time.'

Why shouldn't teachers be expected to mark work? Fair enough they shouldn't be marking as much as they do normally, but (say) 1-2 maths and english tasks per week to be marked is surely reasonable?

There's a wealth of potential labour force for extra teaching

The word ‘potential’ is doing a lot of heavy lifting there.

If there’s so much potential for extra teaching, why the fuck are we so short of it for actual teaching?

People don’t want to do it.

Looks like you're already there -plenty of time to post on MN on a school day

I work part time. Is that OK with you?