Politicians and constitutional experts threw their weight behind proposals sent to Downing Street this week to end a 300-year-old ban on Catholic monarchs.

Labour backbencher Chris Bryant's proposals call for a repeal of the 1701 Act of Settlement preventing Catholics from succeeding to the throne and laws giving males precedence over elder daughters in the royal line of succession, according to a report in The Guardian newspaper this week.

Bryant, a former vicar, said in a pamphlet published by the Local Government Association last week that it would almost qualify a breach of human rights to insist that future monarchs swear to preserve the Church of England, according to Press Assocation.

His proposals have drawn support from Lynne Featherstone, the Lib Dems' spokeswoman on equalities issues, was quoted by The Guardian as saying: "This is an overdue but welcome move. Whilst the hereditary principle itself is obviously still a bit dodgy, at least this modernisation ends the outrageous discrimination against Catholics and women."

Alex Salmond, the Scottish first minister, was quoted as saying: "I welcome these moves. The Act of Settlement is an 18th-century anachronism that has no place in a modern 21st-century constitution. The SNP first raised the issue over a decade ago, the Scottish parliament united in 1999 to call for this long overdue reform, and I hope the prime minister follows through in early course."

A spokesman for Downing Street, however, played down the suggestion that the Government was considering changing the law, according to Press Association.

The spokesman said: "To bring about changes to the law on succession would be a complex undertaking involving amendment or repeal of a number of items of related legislation, as well as requiring the consent of legislatures of member nations of the Commonwealth.

"As the Secretary of State for Justice said in the Commons on March 25, we are of course aware of the concerns felt by many and we are always ready to consider the arguments in this complex area."