A week of hearings began yesterday on a bill to allow same-sex couples in Vermont, US, to marry.

If approved, the state would join Massachusetts and Connecticut as the only US states that allow gay marriage.

Civil unions in Vermont were legalised in 2000 but offered only some of the benefits available to straight married couples.

The new bill will grant gay and lesbian couples access to Social Security benefits available to straight married couples. They would also be able to claim joint health insurance and make emergency medical decisions.

According to opponents, the bill will undermine traditional marriage, render men and women interchangeable and destroy the connection between children and marriage.

However, polls have suggested the state is in favour of the move.

A poll of 7,000 Vermont citizens last March showed that 54 per cent supported gay marriage, while only 37 per cent were opposed. A smaller survey taken in January suggested that 58 per cent were in favour of or leaning towards gay marriage.

Some critics have questioned why the cash-strapped state should consider the bill at this time, but figures from the Williams Institute have suggested that extending marriage rights to gay couples will boost Vermont’s economy by over $30.6 million in three years.

A public hearing for the bill will be held on Wednesday.

Last week, leading mental health organisations in Vermont voiced their support of gay marriage, claiming it will validate relationships, increase benefits for the families and could reduce discrimination.

WCAX.com reported that the Vermont Psychological Association, the Vermont Psychiatric Association, the Vermont Association of Mental Health Counselors and the Vermont chapter of the National Association of Social Workers all said legalising gay marriage would help the children of same-sex couples and provide happier families.