The British government's view about its role in the world in the medium- and long-term is "unrealistic," a critical report by a panel of senior lawmakers said on Thursday.

London needed to plan for a changing, and more partnership-dependent role in the world, said report issued by the parliamentary Joint Committee on National Security and Strategy (JCNSS).

The JCNSS, whose members include two former foreign secretaries and the former head of the security service MI5, annually reviews the British government's National Security Strategy (NSS).

The NSS, published in 2010, said the country would maintain its position as a major world power despite budget constraints and the rise of developing countries.

"This is wholly unrealistic in the medium to long term," the report said.

It criticized the British government for the lack of an "overarching strategy," a document designed to guide government decision-making and crisis management in the international and domestic areas.

The report said there had been no evidence that the NSS has influenced decisions made since October 2010.

"A good strategy is realistic, is clear on the big questions, and guides choices. This one does not. We need a public debate on the sort of country we want Britain to be in future, and whether our ambitions are realistic, given how much we are prepared to spend," said JCNSS chairwoman Margaret Beckett.

"We welcome the setting up of the National Security Council, but it seems to have got side-tracked into short-term crisis management," she said.

The committee said it was concerned that the "National Security Council's oversight of security issues is not sufficiently broad and strategic," given that it was overwhelmingly involved with operations in Libya, meeting 60 times on the issue, and failed to discuss the national security implications of the eurozone debt crisis or the possibility of Scottish independence.

It said government ministers needed to "keep their eyes on longer-term strategy and on risks emerging over the horizon. The NSC seems to be focusing too narrowly on international affairs. That leaves us vulnerable, as threats to our security do not just come from abroad."