A train company has been branded a "disgrace" by union chiefs after it emerged some of its expanded fleet will have no toilets on board.

Southern Railway is refurbishing old trains to help overcrowding on the Portsmouth to Brighton service.

The RMT union said on a journey of that length it was "unacceptable".

Southern said: "The trains were built without toilets and have been used successfully for many years without them."

The entire journey from Portsmouth to Brighton can take up to an hour-and-a-half, but the firm said the trains would be used for short journeys, where most people travel for less than half an hour.

'Stinking cattle trucks'

Independent rail passenger watchdog Passenger Focus said the decision was a blow for passengers who were elderly, had medical conditions and travelled with children.

One and a half hours without any toilet facilities on board is unacceptable Bob Crow, RMT general secretary

Southern Railways said the class 313 trains, which will be introduced in December, had more seats than those currently used on the route.

The trains they replace will be used to provide more coaches on the busiest and most crowded services on the network, it said.

But RMT general secretary Bob Crow called the move "unacceptable" and said it runs the risk of turning carriages into "stinking cattle trucks" creating appalling conditions for passengers and staff.

"The route has always had toilets on board in the past," he said.

"This is the main connection between two major cities on the south coast.

"One and a half hours without any toilet facilities onboard is unacceptable."

He said RMT was already set to ballot members of Southern Railway for industrial action after cuts to security led to an increase in assaults on staff.

More station toilets

Southern Railway said in a statement: "We have made a commitment to increase the capacity of our fleet by 10% so we are introducing extra trains.

"We want to do this as soon as possible and using existing trains that are already available is the best option to achieve this.

"These trains are not newly built though they are being refreshed with an interior paint, new seats and flooring, and flexible spaces for wheelchairs and cycles making them feel 'as new'.

"We will use them in areas where short journeys are typical, such as along our south coast route between Brighton and Portsmouth which is a 'stopping service' on which 90% of passengers make journeys of less than half an hour.

"Not all services between Brighton and Portsmouth will be operated by trains without toilets - approximately two-thirds of those services will still have toilets.

"We are increasing the number of toilets at stations."

Anthony Smith, chief executive of Passenger Focus, said: "This is definitely a blow for passengers, especially those travelling with children.

"However, these changes will help to reduce overcrowding which will be welcomed by passengers.

"Our research shows that passengers are unhappy with station toilets, so it is essential that Southern improves them quickly."