Business chiefs have urged the Prime Minister to be more specific about how he plans to drive growth in the UK, as he pledged to re-establish economic stability, tackle inflation and boost innovation.

Tony Danker, director-general of the Confederation of British Industry (CBI), said it was “great” to hear Rishi Sunak speak about his “deeply held convictions and passion” for innovation, as well as the benefits it can reap on the economy.

But he said the PM only began to lay out his vision for a “new approach” in a speech to the CBI’s annual conference on Monday, as he called for more detail to help businesses invest with confidence.

Mr Sunak also largely avoided directly answering the CBI’s demands for immigration to be used to plug gaps in the domestic workforce, saying the UK’s focus is on tackling the small boats crisis.

However, he did say that he wants to ensure Britain is a “beacon” for the “best and brightest”, vowing to create “one of the world’s most attractive visa regimes for entrepreneurs and highly skilled people” as he set out plans for artificial intelligence experts to come to the country.

Downing Street later said businesses were being encouraged to invest in Britons rather than rely on workers from overseas.

Mr Danker said: “It was great to hear the Prime Minister’s deeply held convictions and passion for innovation, and the role it can play as one of the most important drivers of the UK’s future economic growth.

“The Prime Minister started to lay out a vision for a new approach. But what we didn’t get today are the details of the measures to achieve it.

“Businesses are making investment decisions now and need to hear more on this agenda as soon as possible.”

The CBI director-general has said a more liberalised stance on immigration is needed to help boost economic growth when public spending is tight.

But Mr Sunak said: “The country’s number one priority right now, when it comes to migration, is tackling illegal migration.

“When people see that happening, it undermines trust in the system, it doesn’t seem fair that people are able to break the rules.

“That’s what I’m absolutely determined to fix.”

Mr Sunak said it was “not a simple problem to solve” and would not be dealt with overnight, but he was “determined to reduce the number of illegal migrants coming here”.

He said, “part of the reason we ended the free movement of labour was to rebuild public consent in our immigration system”.

Reducing “illegal” crossings is key to instilling “trust and confidence” in the British set-up, so businesses can access the “best and brightest” from around the world, he added.

The Prime Minister’s official spokesman also said tackling the small boats crisis is top of the agenda on migration.

“It is simply factual that whilst we have tens of thousands of people coming in through the small boats route, we won’t be able to confidently predict what net migration will be because we simply don’t have control over that,” the spokesman said.

Earlier, Mr Danker told BBC Radio 4’s Today: “When it comes to immigration, it’s quite interesting, when you look at the OBR report on Thursday, they said the only thing that’s really moved the needle on growth is by allowing in a bit more immigration.

“The reason why it’s so important is we have literally over a million vacancies in this country, we have 600,000 people who are now long-term unwell, who aren’t coming back to the labour market any time soon.

“That’s why we have to get this shortage occupation list – the list of people that we’re really missing that we aren’t going to get in Britain any time soon – and we have to get them to plug the gap while we re-calibrate the labour market in the medium term.”

Meanwhile, Mr Sunak suggested at the CBI conference that an increase in productivity through developments in robotics and automation could reduce some pressure on the labour market.

He also said the UK is committed to using its “Brexit freedoms” to drive innovation.