Shipping giant P&O is to close four of its 13 ferry routes with the loss of about 1,200 jobs, it was announced today.
Reducing the number of ships it operates from 31 to 23, the company said it would be closing all its Western Channel routes except Portsmouth-Bilbao.
The move, which is being bitterly opposed by shipping union the RMT, is expected to save £55 million a year.
P&O said its tourist traffic had been "adversely affected by fewer day trips and the expansion of the low-cost airlines".
It added that on its Western Channel routes the number of ships operated will be reduced from six to one.
One of the surplus ships will be redeployed elsewhere, one will be redelivered to the owner and three will be chartered out - two to Brittany Ferries and the other subject to ongoing discussions with third parties.
On the Dover-Calais route, six ships will be operated compared with seven at present but, through rescheduling, service frequency and capacity in peak periods will be unchanged.
The company added that "new, more flexible manning arrangements and changes in work practices are proposed".
The company also said that as many as 350 jobs would be transferred.
P&O chief executive Robert Woods added: "I am determined to see a major improvement in the profitability of P&O Ferries.
"What we are announcing today will enable us to have a simplified, customer-focused product operated on fewer routes with fewer ships and a substantially lower, more flexible cost base.
"Whilst we greatly regret the possible job losses, we are convinced that what we are proposing is the best way forward for the long-term prosperity of the business."
The restructuring, which the company hopes to be largely in place by the middle of next year, will mean the axing of the Portsmouth-Cherbourg, Portsmouth-Caen and Portsmouth-Le Havre routes as well as Rosslare-Cherbourg.
P&O currently employs 3,600 sea-going staff and 2,500 shore-based workers.