(Jenny Taylor adjusts a wedding cake figurine of a couple made up of two men at the Gay Wedding show at the Town Hall in Manchester, November 6, 2005/Ian Hodgson.)

Britain looks set to legalize same-sex marriages in the next year or two but legal safeguards it will add to protect the Church of England from having to conduct them may not survive the expected court challenges to them.

Presenting the government’s proposals on Tuesday, Culture Secretary Maria Miller promised that a “quadruple lock” of legal safeguards would bar any judge from forcing the Church to perform the gay nuptials that its leadership opposes.

“The chance of a successful legal challenge through domestic or European courts is negligible” under a bill being drawn up, she told parliament, calling the planned safeguards “iron-clad”.

Legal experts are not so sure. English courts should uphold the law, but the European Court on Human Rights (ECHR) – the Strasbourg tribunal where Europeans can appeal verdicts by their domestic courts – could override a national ruling.