How damaging could further strikes at the Port of Felixstowe be?

Beginning on September 27, the industrial action will last a total of eight days and will cross over with ongoing walkouts taking place at the Port of Liverpool for seven days.

"There are a number of things to be worried about," said Samir Dani, professor of operations and supply chain management at Keele University.

"Supply chains will be under pressure and, with the clash at Liverpool, trade could be seriously affected.

"If ships have to be diverted, we could also see prices go up."

Last month, Unite members voted in favour of strikes - the first since 1989 - by a majority of 92% as part of an ongoing pay dispute.

With the union holding out for a 10% rise, there appears to be no immediate solution in sight.

"The last strikes didn't have a huge impact," said Professor Dani.

"Some shippers diverted their traffic elsewhere, but the industry wasn't near its peak at that point.

"However, there is more concern around this second round because of Christmas.

"Now is the time a lot of people will start buying so pressure on supply chains will be worrying some businesses."

Felixstowe handles nearly half of the containerised freight entering the UK and the disruption could mean vessels have to be diverted to ports elsewhere in the UK or Europe.

Professor Dani warns the threat of further strikes could lead to the site eventually being bypassed by shippers.

"We have not had strikes like this for a long time," he said.

"If this uncertainty continues, companies may choose to avoid Felixstowe altogether.

"Of course, some European and American ports have also faced industrial action so this isn't unique to us.

"But if it continues and it happens another two or three times, shippers may start questioning the site's reliability.

"At the moment, there is a lot of uncertainty so we will just have to watch and see how it unfolds."