Children's commissioner Anne Longfield has called for children to return to school at the "first opportunity possible", as many children have not attended school so far this year.
The Government announced in early January that schools would only open to vulnerable children and those of key workers, after losing a huge proportion of their on-site schooling last year in the first lockdown.
Now Ms Longfield has told BBC Breakfast: "What we all realise now is the impact on children of not being in school, both educationally and in terms of their wellbeing is absolutely immense, and one that we hadn't really anticipated in the first instance but now a year on is very clear to see."
Pupils excluded for breaching Covid rules
19 photographs of Hebburn Comprehensive School pupils arriving in style for their leavers prom night
Assistant head at South Tyneside school given teaching ban for awarding false marks and swapping pupils' work
South Tyneside headteacher 'thrilled' with good Ofsted judgement at ‘kind and friendly’ school
15 photographs of Year 11 St Wilfrid's pupils enjoying the return of their prom night after Covid cancellations
Asked about the lack of equipment affecting some children's ability to learn remotely, Ms Longfield said the pandemic had drawn attention to the difficulties vulnerable children face, terming it "a real eye-opener".
She continued: "At the heart of all this is that children are getting very different experiences and in every likelihood, those children who started behind and most disadvantaged have fallen further behind, we know that now.
"The pressure now on getting that catch-up in place, getting children to the point where they can start to get their confidence back and rebuild really needs to start in huge earnest.
"Which is why I'm really pushing for not only a kind of one year catch-up, but something that will go over the next two to three years to try to get children, as many as possible, not only back to where they should have been but also ahead."