Staff resorted to working on a picnic table in a car park after a property dispute between British Airways (BA) and insurance giant Norwich Union.

About 30 people turned up to work at their offices in Eastman House, Fleming Way, Crawley, to find the doors locked and learn they were being evicted without notice.

In the ensuing chaos, firms had to resort to makeshift offices in whatever space they could find.

Workers from Enterprise Rent-A-Car UK set up outside, running their business from the car park, using mobile phones.

A total of 20 companies have suffered as a result of the dispute.

The freehold of Eastman House is owned by Norwich Union, which had let the building on a long lease to BA, which had, in turn, leased it to a company called Airport Parking Associates (APA).

BA said APA had then sub-let, as serviced offices, to the 20 companies.

When Norwich Union learnt of this it slapped a writ on BA ordering it to clear the building or face eviction itself, saying sub-letting had breached the terms of its lease.

Karen Vyse, director of Peak Assistance, whose company is affected, said: "We were given a letter and a number to call so we could make arrangements to get access to the office and get our equipment.

"I run an office service company doing telephone answering for a number of companies and have a lot of equipment in there.

"It is not something I can throw into a car. It is a totally unexpected upheaval.

"I know BA has said this is inconveniencing them as much as us but I don't think it is the same level of inconvenience to a company such as BA compared with a company like us."

A BA spokeswoman said: "We regret having to take this action but it was necessary. BA is a tenant of Norwich Union, which made it very clear it wanted the situation with APA remedied.

"When an agreement like this is terminated, unfortunately it means all other occupiers lose their right to be in the building."

BA was working hard to help the companies with removing their equipment from the building and explaining what was happening.

The spokeswoman said: "Most have been understanding although, of course, some tenants have been caused inconvenience.

"We have allowed several staff to enter the building today to collect mail, pick up other important documents and equipment and reroute their phones and we will do whatever is reasonable to help sustain the continuity of their businesses."

BA has said it will be consulting with Norwich Union to make sure the building is reoccupied under a proper tenancy agreement.