The British government has announced plans to create new powers that would enable it to more easily block takeovers of United Kingdom companies by foreign enterprises.

The sweeping new provisions that would let London stop selected takeovers on national security grounds have not yet been approved by the nation's lawmakers but will be debated in the coming weeks. They are contained within the amended National Security and Investment Bill, which was published on Wednesday.

The document, which the Guardian newspaper says amounts to "the biggest shake-up in the UK's industrial intervention policy for nearly two decades", allows ministers to retrospectively halt acquisitions up to five years after they happened.

Critics fear it may be used by anti-China elements to curtail Chinese investment in the UK economy.

The Guardian said anti-China lawmakers within the ruling Conservative Party were buoyed by their success in forcing Prime Minister Boris Johnson to exclude the Chinese technology giant Huawei from future participation in the UK's 5G networks, and pushed for the change.

Some of those elements are also believed to be opposed to China General Nuclear participating in future projects in the UK.

The anti-China mood among some lawmakers led last month to member of Parliament and former Conservative Party leader Iain Duncan Smith calling for a full review of Chinese ownership of UK enterprises.

But Business Secretary Alok Sharma insisted the UK is one of the world's "most attractive investment destinations" and said "we want to keep it that way" even though "hostile actors" must be in no doubt "there is no backdoor to the UK".

The government is not thought to be targeting the new rules specifically at China, however. Elements within the government have also called for more scrutiny of Russian acquisitions, and those of many other nations. Johnson and his Cabinet even faced criticism last year when the UK defense and aerospace company Cobham was bought by a United States-based private equity company.

The proposed new rules would allow all takeovers and mergers that involve overseas companies to be referred to the newly created Investment Security Unit within the Department for Business, Energy and Industrial Strategy. Reviews should take no more than 30 days.

The BBC said the old version of the bill had only led to government intervention on 12 occasions since 2002. The Financial Times said British officials expect the new bill to mean around 1,000 transactions a year will be reviewed in 17 key sectors of the economy that include energy and cryptography.

The legislation that will be replaced allowed for takeovers and mergers to be scrutinized if the target asset had an annual turnover of more than 70 million pounds ($93 million), or if the new enterprise would end up with more than 25 percent of the market share.

The new rules would remove such caveats and allow any transaction involving an overseas entity to be scrutinized.

Nicole Kar, UK head of competition law at Linklaters and a specialist adviser to the Commons Foreign Affairs Committee, told the BBC the new rules amount to "a real step-change in terms of government powers".

"There's been a lot of concern around foreign investors buying up startups," she said. "I think there's a real feeling in the government that more needed to be done."

But Veronica Roberts, a partner at law firm Herbert Smith Freehills, told the Financial Times the rules will be "unsettling" for foreign investors and "could be enough to disadvantage some bidders in fast-paced auction processes".

Companies that fall foul of the rules could face fines of up to 5 percent of their worldwide turnover, up to a maximum of 10 million pounds.

Supporters say the tightened rules simply bring the UK in line with other nations, including France, Germany, the US and Australia.