It exposed the personal data of 40 million voters as the commission held the name and address of anyone in the UK who was registered to vote between 2014 and 2022, as well as the names of those registered as overseas voters.
Dowden said any hostile cyber activity directed towards UK parliamentarians was “completely unacceptable”.
He said the two cyber attacks demonstrated a “clear and persistent pattern of behaviour that signals hostile intent from China”.
Foreign Office officials said the majority of MPs and peers who were spied on by Beijing were “prominent in calling out the malign activity of China”.
‘Critics won’t be bullied into silence’
The National Cyber Security Centre (NCSC), part of GCHQ, said Parliament’s security department “identified and successfully mitigated” the cyber attacks “before any accounts could be compromised”.
On Monday it emerged that Lord Cameron, the Foreign Secretary, has called in Wang Yi, the Chinese foreign minister, for a dressing down over the attacks.
The NCSC will publish new guidance for organisations involved in coordinating elections, such as local authorities, which will advise officials on how they can step up the protection of their electoral management systems against cyber hacks.
Earlier on Monday, Sir Iain Duncan Smith said China critics would not be “bullied into silence” as he compared the West’s approach toward Beijing to 1930s appeasement.
Britain has been “too passive” towards China’s overseas influence and has “turned a blind eye” to its malign activities, the former Conservative leader said.
He spoke at a hastily-arranged press conference in Westminster alongside Tim Loughton, a former minister, and Stewart McDonald, a Scottish National Party MP.
Sir Iain, who has been sanctioned by Beijing, said: “Together with other Members of Parliament, activists and dissidents, we have been subjected to harassment, impersonation, and attempted hacking from China for some time. Neither we, nor other parliamentary colleagues, will be bullied into silence by Beijing.
“For years the behaviour of the Chinese government has gone unchecked. We have been too passive as Beijing’s overseas influence operations have rapidly expanded, turning a blind eye to what the intelligence and security committee termed penetration of ‘every sector of the UK economy’.
“We need to be much stronger and tougher. The lesson we learnt from the 1930s, appeasement never works – if you are strong, and you tell them what is wrong and you tell them you are not going to put up with it, then eventually they will probably back down.
“But if you don’t, they just keep taking advantage of you and that is our biggest problem.”
Sir Iain said he found it “incredible” that there is still a debate within the Government over whether or not China will be in the enhanced tier of the new foreign influence registration scheme.
“Still, the UK has yet to impose a single sanction upon officials responsible for the destruction of freedoms in Hong Kong, despite the UK being one of the two duty bearers, with China, under the Sino-British Joint Declaration,” he said.
“The United States, by contrast, has sanctioned over 40. We must now enter a new era of relations with China, dealing with the contemporary Chinese Communist Party as it really is, not as we hoped it would become.
“Today’s announcement should mark a watershed moment where the UK takes a stand for values, human rights, and the international rules based system, upon which we all depend.”
