It is “frustrating” that the government is yet to clarify the circumstances that would trigger moving secondary schools to a rota system, heads have said.

Given that the situation is “clearly precarious”, clarity over contingency plans involving rotas would be “helpful”, according to the Association of School and College Leaders (ASCL).

The call for more information comes shortly after the Department for Education (DfE) issued new guidance on how the national lockdown, starting at midnight tonight, will affect schools.

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The guidance states that all secondary schools will be expected to make masks mandatory in communal spaces from tomorrow, with the rule in place by Monday at the latest.

But there is not a single mention of the word “rota” in the whole document.

Geoff Barton, ASCL general secretary, said: “It is frustrating that there is still no information on what circumstances would trigger the government’s own contingency plan for rota systems in secondary schools.

“We appreciate that this is not the intention during the national lockdown but given that the situation is clearly precarious then clarity would be helpful.”

The current local Covid alert level system has three tiers, for “medium” risk (Tier 1), “high” risk (Tier 2) and “very high” risk (Tier 3) areas. Each has increasingly tight restrictions, with Tier 3 being the most severe.

There is also a separate four-tier system for keeping schools open during local Covid-19 spikes that the DfE announced at the start of the academic year.

Tier 2 of the schools framework would involve secondaries bringing in a rota system. The DfE has said decisions to move schools to this tier would be made on a case-by-case basis.

However, tomorrow, the local Covid alert levels will become redundant, as the new national lockdown comes into effect.

When asked by Tes what this will mean for schools, the DfE failed to provide an answer until this afternoon. The department’s position on rotas remains unclear.