MI5 and MI6 have been urged to merge their counter-terrorism operations in an attempt to tackle the influence of al-Qaeda activities in the Pakistan border region on extremists living in London and the North of England.

Nick Clegg, the Liberal Democrat home affairs spokesman, believes that the current division — with MI5 responsible for domestic threats while MI6 operates abroad — is increasingly blurred and unhelpful and should be abolished. The proposal by Mr Clegg, a frontrunner to succeed Sir Menzies Campbell as leader when he stands down, is part of a package designed to harden the party’s position on law and order, an area in which they have traditionally been seen as “soft”. This includes plans for a national anti-terrorism police force and lowering the hurdle faced by the Crown Prosecution Service before charging terrorist suspects.

He also makes a forceful plea for Liberal Democrats to challenge rather than unquestioningly accept economic, social, cultural and policy grievances voiced by many mainstream Muslim communities. He insists that there are limits to liberal tolerance and that the party must not collapse into “lazy relativism”, a message that might make some party activists uncomfortable. He says: “The overarching objective is to separate the grievances of mainstream Muslim communities from the violent intentions of Islamist extremists in order to ensure that the latter can find no tacit succour or refuge amongst the community at large.”

His plan to reform the intelligence communities would mean a combined anti-terrorism intelligence force acting together at home and abroad, answerable to the Home Secretary, freeing MI6 to continue with its core functions, answerable to the Foreign Secretary. This would avoid a “wholesale takeover” of MI6 priorities by MI5-led anti-terrorism operations, which he says many intelligence operatives fear.

Writing in a new book on Liberal Democrat ideas before next week’s conference in Brighton, he said: “Al-Qaeda is believed to have regrouped in the border region of Pakistan and Afghanistan — with direct implications for counter-terrorism in London or the North of England. The terrorist threat makes a mockery of any neat division of labour between domestic and foreign operations.” Mr Clegg also wants to create a national anti-terrorism police force, in the same way that a force has been created to tackle serious crime, rather than leaving the Metropolitan Police to take lead responsibility for the issue.

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