The Ministry of Defence has suffered a significant data breach, exposing the personal information of UK military personnel. 

The department immediately disconnected the external network operated by a contractor. 

The hack targeted a third-party payroll system used by the MoD, which contains the bank account information and names of former and current members of the armed services. It is also possible that a very small number of addresses were accessed.    

The BBC and Sky, who first reported the story, initial investigations had found no proof that data had been removed. According to the data obtained by The Guardian, the defense secretary, Grant Shapps, is scheduled to make a statement in the afternoon following the Tuesday Commons debate. 

Ministers will point at hostile and malign actors without identifying the country responsible for the cyberattack.   

As a precaution, affected service staff will be notified and given expert guidance. They can use a personal data protection service to find out if their information is being used or if there is a plan to use it.   

All salaries were paid at the last payday, and nothing unusual is expected for the one that comes at the end of this month. However, there might be a slight delay in paying expenses in a few instances.   

The shadow defense secretary, John Healey, said, "So many serious questions for the defense secretary on this, especially from forces personnel whose details were targeted."

He added that any such hostile action is utterly unacceptable.

After learning about the incident a few days ago, the MoD has attempted to confirm its scope and consequences. In March, the US and the UK launched an unprecedented joint operation to expose Beijing's espionage, accusing China of launching a global campaign of "malicious" cyberattacks.