MPs have attacked the government's decision to allow Huawei technology to be used in the UK's 5G mobile networks.
Some called for an outright ban during a debate in the Commons, arguing even limited access put UK security at risk.
But Foreign Secretary Dominic Raab said the decision followed a "rigorous" review by security experts and "tight restrictions" would be in place.
They include a ban on using the Chinese firm's technology in so-called "core" parts of the network.
The firm's kit will also only be allowed to account for up to 35% of the network's peripheral equipment.
Huawei has always denied it would help the Chinese government attack one of its clients.
Its vice president, Victor Zhang, welcomed the UK's decision, saying it would "result in a more advanced, more secure and more cost-effective telecoms infrastructure that is fit for the future".
Boris Johnson has sought to allay US security concerns about Huawei's involvement in a phone call with President Donald Trump.
Downing Street said the prime minister had "underlined the importance of like-minded countries working together to diversify the market and break the dominance of a small number of companies".
Mr Trump has yet to comment publicly on the UK's decision although the White House has said it is "disappointed" and a number of US politicians have warned of the possible repercussions.
Giving a statement to MPs, Mr Raab said: "I hope the whole House will agree that if we are to achieve our digital connectivity ambitions, it is absolutely imperative that we trust the safety and security of our telecom networks.
"Risk cannot be eliminated in telecoms. But it is the job of government, Ofcom and industry to work together to ensure we reduce our vulnerabilities and mitigate those risks."
However, his statement did not reassure a raft of MPs from all sides of the House who criticised the move.
Former Conservative cabinet minister David Davis said "the only way to protect our safety is to ban it", while his backbench colleague Julian Lewis said Huawei was "intimately linked with the Chinese communist state and its deeply hostile intelligence agency".
The SNP's John Nicholson said the firm's technology was "not safe" to use and the government had "chosen low cost over security".
His colleague, Carol Monaghan, said she did not know if it was "naivety or arrogance preventing the UK government from seeing the high risk being presented to security".
Earlier, Labour's shadow culture secretary, Tracy Brabin, criticised the government for "failing to invest in home-grown alternatives to Huawei", which she claimed put them in the "ludicrous position of having to choose between the UK's security concerns and our infrastructure needs".
That issue was raised by a number of MPs, including the DUP's Sammy Wilson, who asked for assurances from Mr Raab that "in future [the UK will] not be as dependent on foreign technology".
Tory Iain Duncan Smith said it "beggars belief" that the firm was given the green light when the UK had "a cyber war going on with China".
He urged the government to ensure it was "driven out" of the UK market as soon as possible.
The foreign secretary admitted there were only three major vendors that made kit suitable for 5G networks - Huawei, Ericsson and Nokia - and it was a "market failure that needs to be addressed".
He added: "The government is developing an ambitious strategy to help diversify the supply chain.
"This will entail the deployment of all the tools at the government's disposal, including funding."
Five big decisions for Boris Johnson
By BBC News online political reporter Jennifer Scott
It's only six weeks since Boris Johnson stormed to victory in the general election - winning with an 80-strong majority - but the honeymoon is over and the prime minister now has serious government business to attend to.
The coming few weeks demand some big decisions from Mr Johnson and his cabinet.
Huawei was the first - but what are the others? Find out here.
Despite the backlash in Parliament, other MPs have welcomed the government's decision.
Former Prime Minister Theresa May said the government had made "the decision that protects our national security but also recognises the interests of economy."
Former Culture Secretary Jeremy Wright said it seemed to be a "sensible compromise" and Huawei technology could be used as long as the government was "sensible, cautious and following the advice of the intelligence agencies".
Labour's Kevan Jones a former member of the Intelligence and Security Committee - also told MPs he had seen nothing to suggest the decision would compromise the UK's intelligence relationship with its key allies.
Today's decision marks a significant gamble by Boris Johnson.
The hope within government is that the restrictions imposed on Huawei will be enough to avoid a major breakdown in relations with the United States and appease critical Tory MPs.
At the same time, however, it's hoped the restrictions will be sufficiently light touch not to delay the roll-out of super fast broadband - thereby compromising Boris Johnson's election pledge to "level up" living standards outside of London and the south.