Nicola Sturgeon has admitted that schools were likely to see outbreaks of coronavirus, on the day many pupils returned to classrooms in the wake of the Covid-19 lockdown.

In facing questions on the effectiveness of Test and Protect, the measures brought in at the end of May to contact trace any outbreaks, she appeared to accept the risks of infection in schools.

She told MSPs: "We will in all likelihood see outbreaks of coronavirus in schools, and in secondary schools, perhaps, in particular.  It is how we contain those and make sure that those are properly dealt with that is the really important thing.

"I want to give the chamber assurance that that is absolutely an issue of priority focus for the government."

It comes after a poll of nearly 30,000 teachers in Scotland outlined serious safety concerns in advance of primary and secondary schools beginning a phased re-opening from yesterday.

Some 81.9% have said they registered varying degrees of a lack of confidence over the ability to keep the required 2m distance in the classroom.

Three in four have said they feel unsafe returning to school with the majority saying they feel uncomfortable teaching without social distancing between pupils.

Ms Sturgeon spoke out while being quizzed on how effective Track and Trace actually was in the aftermath of the cluster of Covid-19 cases in Aberdeen.

Willie Rennie leader of the Scottish Liberal Democrats responded: "I am equally sure that is why the First Minister understands that people are very nervous about what is going to happen following the opening of the schools."

Ministers have admitted it is unable to demonstrate the effectiveness of its flagship coronavirus track and trace system - in advance of the opening of schools.

The Herald on Sunday revealed that while details on the effectiveness of contact tracing south of the border have been available for weeks in advance of their schools opening in September, the success or otherwise of Scotland's two-and-a-half-month-old Test and Protect system is not expected to be in place till the end of the month.

A source when asked why it is taking so long said: "The National Contact Tracing Centre and Public Health Scotland is continuing to work with CMS [Case Management System] users across the territorial boards to improve data quality ahead of publication."

Last week scientists in a study warned the current testing and contact tracing south of the border was inadequate to prevent a second wave of coronavirus after schools reopened.

This is because the contact tracing system must reach at least 68 per cent of people who have tested positive for coronavirus, and their contacts, in order to contain the spread.

However, the current system south of the border at the time of the study reaches 50 per cent of contacts and only a small fraction of symptomatic cases are tested, according to researchers from University College London (UCL) and the London School of Hygiene and Tropical Medicine.

he researchers found the most recent data showed about 81% of positives being interviewed, about 81% of those reporting contacts and about 75% of those contacts being reached equating to 50% coverage.

READ MORE: No trace - Concern as effectiveness of Scotland's coronavirus tracking cannot yet be demonstrated

The Scottish Government's Test and Protect policy kicked in on May 28 to ensure there was no further spread of Covid-19 and there has been increasing calls to ensure it is fit-for-purpose as the country opened up to tourists last month and before children return to school on Monday.

In Scotland, there is so far no track on the percentage of contacts treached that can be scrutinised by experts.

The Scottish Government is also unable to demonstrate the percentage of positive cases are followed up, or the percentage of those interviewed who report contacts.

The First Minister later said schools guidance includes "a number of mitigating factors to ensure that schools are safe and the right protections have been put in place".

She added: "Again, we will keep that under very very close review."