The First Minister Mark Drakeford has said the Welsh government will keep the plan for schools to return 'under consideration', amidst mounting criticism from teaching unions.
Nine education unions have called on the Welsh Government to give a "centralised, coherent response" to the reopening of schools following concerns about the new strain of coronavirus.
In a joint letter the unions say they "are at a complete loss to understand" how schools can begin a phased return of classroom learning from next week, after it was announced the Covid-19 variant was 70% more transmissible.
However, seeking to address those concerns, Mr Drakeford said the government's position would be guided by evidence.
He told BBC Radio Wales: "Of course we will continue to make decisions in the light of the best knowledge, research and information that's available to us at the time.
"But as a government, we will not lose sight of the fact that we have a generation of young people here in Wales whose lives have been so badly disrupted in 2020, whose education needs to be put back on track.
"And it is their needs we will continue to have at the forefront of our minds as we organise with our colleagues a safe return to school."
The National Association of Head Teachers (NAHT) Cymru has demanded to see the scientific information the government says it is being led by, and has begun legal proceedings to force them to disclose the information.
Ruth Davies, national president of NAHT Cymru, said she was not confident in the current arrangements.
She said: "At the moment we can't really see any solid scientific evidence regarding the impact of the new variant on schools and in particular there is nothing in the published information that we've seen so far that outlines the risk to pupils and teachers of maintaining in-person tuition.
"And quite simply until we have that detail, you'll understand, it is impossible for headteachers to draw up the risk assessment and then for governors and trustees to sign them off."
On Sunday, NAHT Cymru made a series of requests to the government for how it believes the plan for a return to schooling should progress.
Move all schooling to a home and online learning setup for most children
A provision of the technology and learning resources to make home learning as practical as possible
For the government to replace a previously suggested lateral flow testing programme for schools with a new setup that removes the need for teachers to lead school testing
Work alongside Public Health Wales and school leaders to agree on new covid-related safety measures during the temporary home learning period
Prioritise vaccinations in education
Both NEU Cymru and NASUWT also urged Welsh Government to ensure face-to-face learning is delayed.
Dr Patrick Roach, NASUWT general secretary, said the organisation would "not hesitate to take appropriate action in order to protect members whose safety is put at risk as a result of the failure of employers or the Welsh government to ensure safe working conditions in schools."
Mr Drakeford said there was currently no evidence that the new strain caused a more severe illness in young people, although it did "transmit more quickly".
In response to the NAHT's legal proceedings, a Welsh government spokesperson said: "Welsh Government cannot comment on any potential legal action.
"Throughout the pandemic we have regularly published papers produced by our Technical Advisory Cell providing advice based on the latest scientific evidence and we will continue to make this information available.”
Addressing the concerns over schools returning and calls for a shift to home learning, the spokesperson said: "We have agreed with local authorities a common approach to schools returning in January with some flexibility built in over the first two weeks of term.
"It is our expectation that pupils, when not in school, will continue to benefit from remote learning."
Plaid Cymru have called on the Welsh Government Cabinet to meet "as soon as possible" to consider scientific evidence about how the new variant of coronavirus is being transmitted in schools.
Plaid Cymru Shadow Minister for Education, Sian Gwenllian MS also said: “An immunisation programme for all school staff also needs to get underway with a timetable for roll out announced as soon as possible.: