Thousands do it. Patsy and Liam will do it today. But is it time we reformed marriage?

Till death us do part may be too ambitious for Patsy Kensit tying the knot for the third time today at the advanced age of 28.

So here's a solution to her problem - go for a fixed-term commitment with her intended, the Oasis bad boy Liam Gallagher.

This latest proposal to update marriage comes from the think-tank Demos, who think such a radical overhaul of marriage is necessary if wedded bliss is to survive into the 21st century.

Between 1961 and 1991 Britain saw a six-fold rise in the divorce rate, which makes it the highest in Europe and four in 10 marriages are now predicted to end in divorce. The rate of first time marriages has also reached its lowest ebb since 1889.

"With over half of divorces now granted to couples who haven't reached their tenth anniversary even a successful 10-year commitment would be a step forward," said Helen Wilkinson, project director of Demos and author of the report The Proposal.

At the start of the first ever National Marriage Week, Demos is arguing for reforms which it claims would "attract a new generation to marriage". It calls for equal legal marital status for same-sex couples as well as heterosexual couples. Following examples set in Australia and California, couples should be allowed to choose who should marry them, from friends to professional non-religious celebrants.

"These modern day guardian angels should be encouraged to help out when things get difficult by offering advice or putting couples in touch with experts who can better assist them," Ms Wilkinson said.

Perhaps the most radical proposal is that couples without children who feel unable to commit themselves to lifelong marriage should be encouraged to experiment with time-limited partnerships at the end of which they could renew and renegotiate their vows.

The idea of public commitment to marriage remains popular. Only 14 per cent of people believe marriage is out of date and more than four in five 16- to 17-year-olds expect to marry.

Studies consistently show people in successful marriages enjoy better mental and physical well-being, live longer and report being happier. Stable families also bolster children's educational, health and behavioural development and put less strain on the taxpayers' pocket. Already divorce and separation breakdown costs the Government pounds 4bn every year. Tax incentives to marry and legal action to make divorce more difficult have as yet had little discernible effect on the decision to marry.

Ms Wilkinson said the idea of contracts and the renewal of vows "would include the recognition that people and the relationships they build are likely to change substantially.

"We believe fixed-term agreements would tend to strengthen rather than weaken relationships."

But Daphne Cook, chairperson of the national trustees of Flame [Family Life and Marriage Education] said: "I do not believe that you will change anything by changing the outward controls on the relationship called marriage. The only way it will ever change is when individuals see that as a gift from God and a unique opportunity to live together and gain knowledge of one another."

Ms Wilkinson said: "We all need public rituals. They are part of what makes us a community, part of how we signal continuity in society. Unfortunately our rituals have atrophied and lost their passion." She added: "The time has come to give them back to the people they are meant to serve, that they may once again be infused with meaning or emotion."

The Proposal; pounds 4.95; from Demos - 0171 353 4479.

A marriage of true minds, The Tabloid