A battle is brewing over plans to turn so-called spy tunnels beneath central London into "one of the world's most unique cultural experiences", pitting a global financier against local residents.

Australian-born private equity entrepreneur Angus Murray has submitted the proposal to transform the history-rich yet little-known Kingsway Exchange Tunnels — which stretch for over a mile (1.6 kilometers) — into a major tourist attraction.

If approved, it would host immersive displays showcasing its distinctive heritage as a World War II bomb shelter and then the home of the top-secret Special Operations Executive.

A branch of the MI6 foreign intelligence service, it is considered the inspiration for "Q Branch" in Ian Fleming's James Bond franchise.

The reimagined venue, which will boast other exhibits as well as Britain's deepest licensed bar, is aiming to welcome up to two million annual visitors from 2027.

"We envisage The London Tunnels achieving the same iconic status… as the London Eye," Murray said last week as he announced plans to list the venture on the London Stock Exchange.

The company plans to invest £220 million ($280 million).

But in recent weeks concerned residents in the monied corner of Holborn have been digging in, complaining about developers and then visitors accessing the site from their quiet streets.

Local opponents include a British lawmaker and landlords of a psychotherapy and counseling venue.

"I object… on account of such a dramatic change of character to a quiet residential area," one local, James Keay, told Camden Council and the City of London local authorities, which will rule on the planning application.

– 'Vision' –

The complex beneath Holborn was built as an air-raid shelter during the early 1940s Blitz bombings, before MI6 moved in later during the war.