Students face being sent home for “malicious coughing” or making inappropriate jokes about Covid-19 under new rules being drawn up by some schools as the bulk of those in England and Wales fully reopen this week.

The new behavioural guidelines come as the Department for Education said schools should clearly state the consequences for bad behaviour, particularly around new movement restrictions and hygiene rules.

In updated guidance for schools, the DfE also warned: “It is likely that adverse experiences or lack of routines of regular attendance and classroom discipline may contribute to disengagement with education upon return to school, resulting in increased incidence of poor behaviour.”

Schools planning to implement a list of “coronavirus red lines” included the Ark Alexandra academy in Hastings which informed parents that they could result in fixed-term exclusions for pupils.

Breaches would include “deliberate or malicious” coughs or sneezes, “humorous, inappropriate comments or statements” related to Covid-19 and “purposeful physical contact with any other person”.

“Any student that needs to have a fixed-term exclusion during the pandemic will not return to main circulation until a risk assessment and we can be assured that the student will adhere to all our expectations,” Jerome Scafe, network associate principal, said in a letter to parents.

Ark Byron primary academy in Acton, west London, said in a letter to parents that pupils refusing to abide by hygiene routines and social distancing instructions would “immediately be moved to a separate area”.

“Some behaviours (eg coughing deliberately on another person) that were previously ‘simply’ antisocial are now potentially extremely serious,” it added.

The development comes as schools also face calls by the co-founder of one large parents’ campaign group to ensure that their other policies protect children who won’t be wearing masks.

Schools in England will be permitted to make pupils wear masks in busy areas such as corridors under new government guidance last week.

But the policy has alarmed some parents, particularly those with disabilities. Dozens have told the parents’ campaign group UsForThem that they are considering de-registering their children, while some have already done so.

“Given the very low threat of the virus for children, we don’t think that requiring children to wear masks is a proportionate response and we would like schools to be very clear on their policies,” said the co-founder Molly Kingsley.

“Schools should not go above and beyond what they are permitted to do, which is to mandate masks in cases of local lockdowns, but we also feel that attention should be paid to World Health Organization (WHO) guidance. It says that, where masks are introduced for children, the body introducing them has to do an ongoing risk assessment. But it’s not what schools are doing.”