Business leaders have raised concerns about a Tory pledge to double a levy on businesses which employ skilled migrant workers.

The Conservative manifesto promises to cut net immigration to below 100,000 and to double the Immigration Skills Charge, levied on employers that employ migrants in skilled roles, from the current £1,000 annual charge per employee.

The party said this would reach £2,000 by 2022, with the intention to invest the revenue in training UK workers.

However, there are fears the increase could hit firms in the region's tech, science and high-end manufacturing sectors, among others.

Neil Miles, chairman of technology sector group TechEast and chief executive of software firm Inasight, said TechEast had 'reservations' about the Conservatives' approach, particularly around the immigration skills levy.

He said: '[It comes] at a time when many firms are already doing everything they can to train up and employ UK workers. These proposals will worry companies in the high-tech and fintech sectors, regardless of size and region.'

Around 11.8% of the workforce in Norfolk was made up of foreign workers in 2016, with 9.9% of the Suffolk labour force being migrants, according to Office for National Statistics figures.

The Confederation of British Industry (CBI) said immigration policy was the 'Achilles heel' of the Tory manifesto.

Richard Tunnicliffe, regional director of the CBI for the East of England, said: 'In a global race for talent and innovation, UK firms risk being left in the starting blocks because of a blunt approach to immigration.

'The next government can both control migration and support prosperity – it does not need to be an either/or choice.'

Other immigration policies outlined in the manifesto include plans to heighten requirements for overseas students hoping to remain in the country to work after their course has finished, and a pledge to 'increase the earnings threshold for people wishing to sponsor migrants for family visas' for those coming from outside the EU.

The Labour Party has pledged not to place a cap on immigration and said its system will benefit the economy. It could involve employer sponsorship, work permits or visa regulations.