British parliamentarians have blocked a private member's bill aimed at giving women in Britain's Royal Family equal succession rights and lifting the ban on heirs to the throne marrying Roman Catholics.

British Justice Secretary Jack Straw told members of the British House of Commons that the bill wasn't "an appropriate vehicle" to reform the 300-year-old Act of Settlement, designed to secure the Protestant succession to the throne.

Straw could not provide a timetable for when legislation governing changes to the act may come. Liberal Democrat MP Evan Harris, who introduced the private member's bill, said later "the government has dealt a serious blow to the prospects of reform by talking out my bill."

The move to kill the bill comes as British Prime Minister Gordon Brown has begun discussion with Buckingham Palace about making changes to succession and marriage rules.

Brown said in media interviews that people in the 21st century expect issues of discrimination to be dealt with. However, he also indicated the government plans to uphold the Queen's role as head of the Church of England.

"This is a complex issue," his Downing Street office said in a statement. "There is no question of changing the constitutional role of the monarch or of changing the role of the Church of England as the established church."

The prime minister's office said Brown will raise the prospect of reforming the monarchy at a Commonwealth summit in November.

Male heirs are given precedence over female heirs under succession rules laid out in the Act of Settlement.

The Queen's only daughter and second-born, Princess Anne, is 10th in line to the throne. If the proposed changes are approved, she would jump to fourth in line, ahead of her younger brothers Prince Andrew and Prince Edward and their children.

Heirs to the throne lose any future claim to the throne if they marry a Catholic.

Autumn Kelly of Montreal converted from Catholicism to Anglicanism before marrying the Queen's grandson, Peter Philips, last year. The decision allowed her husband to retain his position as 11th in line to the throne.

A small number of royals, including Prince Michael of Kent, the Queen's first cousin, have given up their place in the line of succession in order to marry Catholics.