The Archbishop of Canterbury has called Britain’s marriage laws a “social muddle” in regards to civil partnerships and a recent Law Commission report pushing for unmarried couple’s legal rights.

Dr Rowan Williams said civil partnerships were being too closely associated with marriage and are contributing to an erosion of the institution.

He told the Sunday Times, “Civil partnerships were specifically distinguished from marriage as a set of civil contracts that didn’t necessarily involve sexual partnerships … some government documents suggest a kind of slippage of the understanding about that,”

He said the blurring of definitions is creating social confusion.

“The concept of cohabitation is an utterly vague one that covers a huge variety of arrangements.

As soon as you define anything, you are creating a kind of status that is potentially a competition with marriage or a reinvention of marriage.

“I think one of the problems is trying to solve individual and infinitely varied problems by legislation.”

Dr Williams will make s speech about marriage being the cornerstone of society to coincide with Father’s Day next week.

“I don’t think I need to spell out the research about educational factors that can be traced in children from unstable or broken partnerships.

“That’s not to say that single parents don’t do heroic things and it’s not to say that cohabiting couples aren’t often excellent parents day-by-day … the question is about what institution in the long run best serves those needs.”

He was recently criticised by former Archbishop, Lord Carey for creating splits in the Anglican communion.

A report by the Law Commission last month claimed unmarried couples, including gay partners without a civil partnership, who live together, should be given the right to each other’s wealth after a break up.