Does absence really make the heart grow fonder? Increasing affluence and a demand for personal empowerment are encouraging more people than ever before to take holidays from their relationships. Breaks from long-term partnerships as people embark on overseas trips, retreats in monasteries or walking and reading tours can strengthen rather than weaken commitment, insist their supporters.

The trend has already become widespread in America where a new self-help guide, The Marriage Sabbatical, is poised to become a bestseller. However, it has also been criticised by 'family values' campaigners who say it encourages marital break-up.

Sally Graves, 39, from Surbiton, Surrey, went to India 18 months ago with Voluntary Service Overseas, leaving her partner of six years. 'We both knew I wanted to do it and we'd talked about it properly. You take someone for granted after six years. Then suddenly Steve was not there at all. That's when it hits you. However, that wears off and you start to realise what you're missing.

'I had a fantastic time, but when we got back together it made us both realise we could be very independent people and still have our relationship. After six years there is a feeling of "Where do I begin and where does he end?". It made us stronger individually. Everything has been great since.'

Cheryl Jarvis, author of The Marriage Sabbatical, spent three months away from home in a writers' retreat. She insists that a woman's need for time away from her partner is not a dismissal of him but a 'redefining experience' for her which can be the foundation of much greater long-term happiness.

'I had the time of my life,' says Min Smith, 32, who left her two small children with her husband in Edinburgh while she toured South America two years ago. 'I was away for six months, but we had planned everything carefully. We had kids very soon after leaving university, and I always felt I had missed seeing the world. Leaving was a wrench, but coming back was the most wonderful thing I've ever experienced. My husband knew this was something I wanted to do desperately. He acknowledged that it was a trade-off for all the late nights at the office, the weekends away playing rugby and the cancelled evenings out when his work took over.'

But Smith acknowledges that her time away would have been impossible if she were not married to a well-paid barrister. The family employed a second nanny.

'A long-term relationship does require the ability to adapt,' says Phillip Hodson of the British Association for Counselling. 'The old view about two people becoming one is a mistake, because it raises the question, which one? In the old days it was the man. Now, in order to survive a long-term relationship each person needs to be interchangeable. If relationship breaks work, they could have an ameliorative effect. But people should be careful. There is also a risk that this might just be an excuse to end a relationship.'

Viewers of BBC1's Castaway last year saw this played out when Tricia Prater left her husband, Juan, for a year to 'find herself' on the remote Scottish island of Taransay with 25 strangers. 'You put an attractive woman like Tricia on an island for a year, and sooner or later some stud will be after her,' Juan opined to TV cameras before his wife's departure. The 'stud' turned out to be Trevor from Liverpool, another castaway.

'It's important people don't confuse sabbaticals of this sort with a trial separation,' cautioned Julia Coles of Relate, the relationship advisory service.

'It sounds a great kind of thing to do if you have a good healthy relationship without any buried problems. But if you do have problems, when you come back they'll still be there.'

ben.summerskill@observer.co.uk