Britian’s most senior Catholic and a leading opponent of gay and lesbian marriage, Keith O’Brien, has quit after claims he initiated ‘inappropriate acts’ with his priests.

The Vatican is going to investigate the claims.

Four priests, one who has now left the church, have accused the archbishop of ‘inappropriate behavior’ over 30 years.

The four all work or have worked in the Diocese of St Andrews and Edinburgh.

He is contesting the claims and is apparently taking legal advice.

The Cardinal is 74 and was due to retire in March on his 75th birthday. But his resignation will mean he will not travel to Rome to take part in the election of the next Pope, following the shock resignation of Benedict XVI.

That’s something the alleged victims were keen to ensure, as they felt his journey to Rome would prevent a proper investigation into their allegations.

He was even considered a possible British candidate to be the next Pope.

Benedict XVI has agreed to O’Brien’s resignation and accepted it should take effect today (25 February).

But in bizarre twist, a Vatican statement suggested O’Brien actually resigned on 18 February, even though there was no public mention of him leaving until the allegations against him broke in The Observer newspaper yesterday morning. The four men who have made the claims filed them with the Pope’s ambassador in the week before Benedict’s own resignation on 11 February.

O’Brien has previously compared gay marriage to slavery, claiming it is a ‘violation of human rights’ and slammed its planned introduction by the Scottish and parliament and Westminster as ‘madness’.

He was named Bigot of the Year in 2012 by Stonewall, Britain’s leading gay campaign organization, amid protests by O’Brien’s supporters.