TDs and senators who continue to ignore instructions and use non-encrypted office laptops have been warned that they could be sued.

The Oireachtas Commission, which runs the Dáil and Seanad, has warned those TDs who do not encrypt sensitive or personal data entered on Oireachtas supplied laptops, that they may be "personally liable for all costs and damages which may arise from such loss or theft".

Chairman of the commission and Ceann Comhairle, Séamus Kirk, pointed out that the commission "will not defend or cover the costs arising in any case where the member has failed to avail of laptop encryption".

And in a further threat, Kirk said that any member who continues to ignore the warning will be disconnected from the Oireachtas network.

A commission spokesman said last week that "for security reasons" he could not supply the names of the TDs and senators who have still not encrypted their laptops or how many of the 236 TDs and senators are still operating unprotected laptops.

The commission's main concern is that as it supplies the politicians with laptops, under data protection laws the commission itself – or the taxpayer – could be financially liable if a TD's non-encrypted laptop with sensitive information is stolen or mislaid.

But if the commission makes every effort to force TDs to protect their laptops, then responsibility switches to the individual TDs who refuse to change.

Stolen or mislaid laptops have been a persistent problem for government departments and agencies.

Last July, the HSE admitted that 15 laptops were stolen from an office in Roscommon, one of which contained non-encrypted sensitive information on people who had applied to community officers for assistance.

Another non-encrypted laptop contained a private staff briefing while the other 13 were encrypted and so the information could not be accessed.

In 2008, a public servant lost an un-encrypted laptop at a bus stop. The laptop contained sensitive commercial information of IDA-backed companies operating in Ireland.