THE Catholic Church in Scotland and the Deputy First Minister have criticised the UK Government for not including its most senior leader in a delegation to the Vatican.

Cardinal Keith O'Brien, president of the Bishops' Conference of Scotland, did not join ministers and other religious leaders on a trip this week to mark the 30th anniversary of full diplomatic relations with the Holy See – the episcopal jurisdiction of the Catholic Church in Rome – despite being Britain's most senior Catholic.

Archbishop Vincent Nichols of Westminster, president of the Bishops' Conference for England and Wales, attended the event. Scottish Secretary Michael Moore was also in attendance. However, it is understood there were no Scottish or Irish Catholic representatives.

A Catholic Church spokesman said the failure to invite Cardinal O'Brien was "unfortunate".

He added: "The fact Cardinal Keith O'Brien, the president of the Bishops' Conference of Scotland and Britain's senior Catholic, was not included is a most unfortunate oversight.

"The Foreign Office have been involved in the planning process for several months and should have been aware that within the United Kingdom the Catholic Church is organised into three distinct and autonomous Bishops' Conferences – the Bishops' Conference of Scotland, England and Wales, and Ireland. Strictly speaking all three should have been represented.

"This situation is especially regrettable as one of the members of the Ministerial delegation is the Secretary of State for Scotland Michael Moore, whose constituency is in Cardinal O'Brien's Archdiocese."

He added the church plans to make further representations to the UK Government on the issue.

Deputy First Minister Nicola Sturgeon said: "The UK Government appears to have forgotten about Scotland by not including Scotland's cardinal in the delegation.

"The basic job description of Secretary of State for Scotland is to ensure the Scottish dimension is reflected across Government departments in Whitehall, but the Coalition seems to be either unwilling or unable to show Scotland proper respect."

The delegation, led by Baroness Sayeeda Hussain Warsi, focused on inter-religious dialogue, human rights, the environment, international development and climate change. Baroness Warsi, who was joined by six other ministers, warned of "secular fundamentalists" as she met with Pope Benedict XVI.

She said: "He said he was glad I was making the case for faith. Secular fundamentalists are saying people of faith shouldn't have a voice in the public sphere. I'm saying faith should be one of many voices."

Nigel Baker, British ambassador to the Holy See, said it was rare for a delegation not at head of state or government level to be received by the Pope.

Last night a Scotland Office spokesman said: "The party was made up of ministers. Last week an invitation was extended to Cardinal O'Brien to join the delegation for the official dinner, which was hosted by the Holy See yesterday."

The row broke out on the eve of Prime Minister David Cameron's visit to Edinburgh today to meet First Minister Alex Salmond over the planned independence referendum.