CONCERNS have been raised about the anti-Trident SNP gaining membership of the Westminster committee that oversees the work of the UK's intelligence and security services.

Members of the cross-party Intelligence and Security Committee (ISC) are nominated by the Prime Minister in consultation with the Opposition leader.The group of MPs regularly have access to highly classified information and are bound by the Official Secrets Act.

A senior SNP source, asked about which Commons committees the party wanted to be on now it had 56 MPs, said: "We will be looking to be on absolutely everything. Where the Liberal Democrats were, we will seek to be. We want to be on all the Commons committees as well as all the internal bodies."

Asked if that meant the party would want an SNP MP on the ISC, he replied: "Absolutely."

But Tory backbencher Bob Neill stressed how this could cause alarm among some parliamentarians. "I can understand why some people might have misgivings about a party that has a fundamental disagreement on our defence policy, Trident, being on the ISC."

The Tory Vice-Chairman referred to how the ISC had access to secret security files and noted how the main decision for approving the new generation of nuclear-armed submarines was due in less than a year's time, in early 2016.

"It just might be a bit odd if you have material about the nuclear deterrent being discussed; I can see how that could be a worry," stressed the London MP.

But Mr Neill's Conservative colleague, Bob Stewart, a former Army officer, pointed out that the SNP, given their numbers, would be entitled to seek representation on many Commons committees, including the ISC. "You don't have a choice; that's democracy." Asked if he had concerns about the Nationalists having representation on the ISC, he replied he had none that were fundamental, adding: "I trust them."

And Lord West, the former First Sea Lord and a Security Minister in Gordon Brown's Government, said it was up to the Prime Minister to make appointments to the ISC. "One should not make any assumption they are not going to be patriotic," he said, adding: "They have been elected; they are British MPs."

Alex Salmond, the former First Minister and a Privy Counsellor, is tipped to become the SNP's candidate for the ISC, which is usually made up of seasoned parliamentarians; in the last parliament its members included Sir Menzies Campbell, the former LibDem leader, Sir Malcolm Rifkind, the ex-Foreign Secretary, and Lord Butler, who served as Cabinet Secretary during the Thatcher, Major and Blair governments.

The ISC, established in 1994, looks at the policy, administration and expenditure of the Security Service, Secret Intelligence Service and the Government Communications Headquarters. Reforms in 2013 meant it now has greater powers and an increased remit to look at operational activity.

Its composition is not chosen by the political parties - unlike so-called select committees - but after the Prime Minister and Opposition leader's list of candidates is approved by the Commons.

It also provides oversight of defence intelligence at the Ministry of Defence and the Office for Security and Counter-Terrorism in the Home Office.

The process of forming committees begins this week. A short debate on the subject is due to take place after next Wednesday's Queen's Speech.

It is thought the SNP will be entitled to the chairmanships of at least two committees and is intent on securing that covering Scottish Affairs.

The Nationalists are determined to have MPs on all committees, including those covering the devolved areas of health and education.

Conservative MP James Gray, a former Shadow Scottish Secretary, said he accepted the SNP was entitled to places on committees.

But he added: "It would be quite extraordinary if they sat on committees that examined only English matters."