A third of UK businesses expect a response to emails within two hours, and one in 10 expects a 30-minute turnaround, according to research by Vodafone.

With these increasingly high standards, Vodafone estimates that a lack of mobile email access is costing British business around £7bn a year.

More than a third of respondents are aware of occasions where lack of access to email while out and about has caused unnecessary stress and conflict in the workplace. This figure rose to 48 per cent for those working in London.

"This year we have seen mobile email access become an essential piece of the business armoury," said Mark Bond, director of the Enterprise Business Unit at Vodafone UK.

"This survey clearly demonstrates that the way we approach our work is changing, and that businesses need to move to address that change."

Over a third of those surveyed also felt that the absence of mobile email access led to wasted time while travelling or waiting for meetings.

The figure doubles among workers such as service engineers who spend significant amounts of time outside the office.

Access to mobile email is no longer the sole realm of upper management, the survey found, as 58 per cent believe that all employees will need mobile email access in the future.

The research also suggests that age plays a part in email related stress. A third of younger workers panic when encountering a very full inbox on returning from meetings, and 17 per cent report feeling anxious when 'offline'.