The British government is expected to publicly link China to cyberattacks that compromised the voting records of tens of millions of people, another notable hardening of Britain’s stance toward China since its leaders heralded a “golden era” in British-Chinese relations nearly a decade ago.
The deputy prime minister, Oliver Dowden, will make a statement about the matter in Parliament on Monday afternoon, and is expected to announce sanctions against state-affiliated individuals and entities implicated in the attacks.
The government disclosed the attack on the Electoral Commission last year but did not identify those behind it. It is believed to have begun in 2021 and lasted several months, with the personal details of 40 million voters being hacked.
The Electoral Commission, which oversees elections in the United Kingdom, said that the names and addresses of anyone registered to vote in Britain and Northern Ireland between 2014 and 2022 had been accessed, as well as those of overseas voters.
The commission previously said that the data contained in the electoral registers was limited and noted that much of it was already in the public domain. However, it added that it was possible the data “could be combined with other data in the public domain, such as that which individuals choose to share themselves, to infer patterns of behavior or to identify and profile individuals.”
In addition to the infiltration of the Electoral Commission, Mr. Dowden is expected to confirm that the Chinese targeted several members of Parliament with a record of hawkish statements about China. They include Iain Duncan-Smith, a former leader of the Conservative Party; Tim Loughton, a former Conservative education minister; and Stewart McDonald, a member of the Scottish National Party.
In remarks to reporters before the announcement, Prime Minister Rishi Sunak said, “We’ve been very clear that the situation now is that China is behaving in an increasingly assertive way abroad, authoritarian at home and it represents an epoch-defining challenge, and also the greatest state-based threat to our economic security.”
“So, it’s right that we take measures to protect ourselves, which is what we are doing,” Mr. Sunak added.
Tensions between Britain and China have risen in recent years over concerns about human rights and Chinese threats to British security. Under pressure from the United States, Britain in 2020 announced plans to curtail the role of Huawei, the Chinese telecommunications giant, in its 5G network.
Then Britain condemned a new national security law in Hong Kong, a former British colony, saying it violated the terms of London’s handover agreement with Beijing. The government offered visas to roughly 350,000 Hong Kong residents who held British overseas passports, and about 160,000 had moved by 2023.
In September, the police arrested a 28-year-old British researcher in Parliament on suspicion of working for the Chinese government. The man, who denied being a spy, worked with prominent lawmakers, including Tom Tugendhat, who is now security minister in the government, on China policy, raising fears of possible security breaches.
The arrest of the researcher, which was believed to be unrelated to the cyberattacks, widened a rift within the governing Conservative Party over how London should engage with an increasingly assertive Beijing.
The current foreign secretary, David Cameron, was prime minister during the period when Britain cultivated closer commercial ties with China. In a news conference with President Xi Jinping in 2015, he hailed the dawn of a “golden era in relations between Britain and China.”
Mr. Cameron, who has since stiffened his language about China, is expected to brief Conservative members of Parliament about the allegations later on Monday.
On Monday, a spokesman for China’s Ministry of Foreign Affairs, Lin Jian, dismissed the reports of Chinese hacking as “fake news.”
“When investigating and determining the character of cyber-incidents, there must be adequate objective evidence,” Mr. Lin said, “not smearing other countries without a factual basis, not to mention politicizing cybersecurity issues.”
Christopher Buckley contributed reporting.
