Sussex commuters do the equivalent of half a day's work just getting to and from their desks.

Lengthy journeys by road and rail mean their working day is half as long again. Those Travellers could also be spending up to a third of their incomes on travelling costs.

National research by the RAC Foundation and the Telework Association found commuters add an average of nearly five weeks to their working lives each year just travelling to and from work.

The worst examples were in the South-East, where it is common for commuters to spend four hours or more on the move.

Shelley Atlas, spokeswoman for Brighton Line Commuters, said the figures seemed shocking but would be no surprise to most commuters.

She said: "When things like this are averaged out over a year, they seem excessive but if you look at individual journeys, week by week, they don't seem so bad. Delays add up and of course they are frustrating but when things run smoothly, it is okay."

Ms Atlas said most commuters did not have a choice about whether or not to travel.

Travellers commuting from Brighton to London pay about £2,500 for an annual season ticket, excluding tube travel.

Writer and broadcaster Simon Fanshawe, chairman of Brighton and Hove Economic Partnership, has never owned a car and relies on bikes and trains.

He said: "It is impossible to get across the South-East region. The main roads are as blocked as the arteries of someone who has lived for 30 years on a diet of butter.

"You have to encourage people to use public transport and share vehicles.

"I think companies would improve their productivity if they poured a considerable amount of effort into transport. Employees would not turn up disgruntled and annoyed."

Brighton Pavilion MP David Lepper became a commuter when he entered Parliament.

He said: "I and other MPs have been putting the case to central government for additional investment locally that will attract firms to set up business here and provide more well-paid jobs so people don't have to commute.

"And in the last couple of months, I think there has been an improvement in the fast train service to London."

The RAC Foundation and the Telework Association, an umbrella group which promotes and advises on alternative working locations, want t employees and managers to consider alternatives, including working from home or switching to local employment.

Edmund King, executive director of the RAC Foundation, said: "If each employee would work from home just one day a week, we would see a 20 per cent cut in traffic."