MPs have demanded that the Government block Chinese investment in the UK’s critical infrastructure following concerns of alleged sabotage at British Steel.

Downing Street refused to rule out further Chinese involvement in British Steel despite ministers being forced to take emergency control of the Scunthorpe plant from its Chinese owner Jingye.

Officials are scrambling to ensure there are enough new materials – such as coking coal and iron ore – to keep the North Lincolnshire site running.

Former Conservative leader Sir Iain Duncan Smith warned China is a threat to “everything that we do”.

He said: “When it comes to steel, if they had shut the blast furnace, what they would have done is imported slab steel from China which they would have re-badged as British steel to sell it.

“It would not be high quality steel. It wouldn’t have been virgin steel but a much lower quality.”

He added that the owners would have imported cheaper slab steel from China instead.

When asked whether the Government should block Chinese Investment from the UK’s critical infrastructure, he said: “Absolutely. We don’t want China involved in our critical infrastructure and it’s time the Government define what that was.”

Ministers are now looking for a private sector partner to co-invest in the site, Sir Keir Starmer’s spokesman said.

He did not rule out working with Beijing-based businesses, saying: “I wouldn’t get ahead of commercial negotiations. Our approach, certainly when it comes to China, is rooted in the UK national interest.”

The spokesman also attempted to play down suggestions that the Chinese government was behind attempts to sabotage the plant. “We’re not aware of any deliberate act of sabotage,” he said.

There are no plans for any new review of the involvement of Chinese companies in Britain’s critical national infrastructure but No 10 said that a “rigorous regime” was already in place.

Treasury minister James Murray insisted the Government had “robust processes” to assess Chinese involvement in critical infrastructure.

He said: “There’s already a robust process to look at foreign involvement in critical national infrastructure – whatever country that investment comes from – and that sits alongside our focus on supporting free trade and encouraging investment, foreign investment, from around the world in the UK.

“Our approach is to be very clear that we are open to that investment, whilst being also open-eyed about saying that when there’s foreign involvement in critical infrastructure, whatever country that comes from, we need to make sure there is a high level of scrutiny.”

He added: “I think it’s important to make clear that the actions of Jingye, of one company, don’t speak to the actions of all Chinese companies.

“But we need to be clear that we have an approach where we encourage investment from around the world, and are open to that investment and free trade, but at the same time having these very clear principles of saying when there is foreign involvement in critical infrastructure, they will receive the highest scrutiny.”

It comes as ministers are “confident” that raw materials, including coking coal stored at the Port of Immingham in Lincolnshire, will now be delivered to the furnaces in time to keep them operational.

There are two ships carrying materials docked at the port with a third ship on route to the UK off the coast of Africa.

Angela Rayner said that the raw materials needed to keep Scunthorpe steel plant running have been paid for. It is understood they will arrive in the coming days.

The Deputy Prime Minister said: “We’re confident that we’ve got the raw materials and these furnaces will continue to be fired, and that was really important for the future of British Steel, and the Government stepped in and took the action that was necessary.

“Yes, there’s more that we need to do over the next coming months and years, but this was a crucial step forward for British Steel in the UK.”

Meanwhile China warned the UK against “politicising” the British Steel crisis.

The country’s foreign ministry urged the UK to “treat Chinese businesses that have invested and operate in the UK fairly and justly, (and) protect their legitimate and lawful rights and interests”.

Spokesman Lin Jian said the UK should “avoid politicising trade cooperation or linking it to security issues, so as not to impact the confidence of Chinese enterprises in going to the UK”.

Senior Conservative Sir David Davis MP said the UK government should have a “golden share” for any major industry which trades on the international market, including steel and life sciences.

He added: “A golden share allows you basically to stop the owners doing certain things, selling it for other people, and so on and, depending on how you draft a golden share, shutting it down.

“In the modern world we probably should have golden share for any major industry that’s in play in the international market.”